Houckster,
I don't have a link but here is the report
sorry for the length)
Experimental Evaluation of Motor Oils
for Use in State Vehicles
Jarno Kilian
Robert M. Rutherford
Dr. Elsayed M. Afify
Dr. James W. Leach
Mechanical and Aerospace Engineering Department
North Carolina State University
July 3, 2002
for
NC Department of Administration, Energy Office
1
Summary
his report documents four separate tests conducted under the supervision of the North
,
be
hassis dynamometer tests known as the Federal Test Procedure (EPA 75 city) and
e
ed
rs
Details
Table 1 EPA 75 and HWFET Test Results for DPS1
T
Carolina State University and the North Carolina State Highway Patrol to compare fuel
economy and exhaust emissions from typical service vehicles and from research engines
operating with a proprietary oil (Royal Purple Oil) and with other competitive oils. The
tests are not intended to supersede Society of Automotive Engineers tests required for
American Petroleum Institute Certification. The API tests have already been conducted
and have established the suitability of each of the oils for use in modern engines. The
current tests were designed to provide data from one-against-one performance tests to
used by the State of North Carolina for economic evaluations.
C
Highway Fuel Economy Test Procedure (HFET) were conducted in an independent
laboratory in San Antonio, Texas. These two tests are the only tests recognized by th
EPA National Vehicle and Fuel Emissions Laboratory Motor Vehicle Aftermarket
Retrofit Device Evaluation Program. The Texas Department of Public Safety provid
two 4.6-liter Ford Crown Victoria Highway Patrol Cars for the EPA tests. The patrol ca
were year 2,000 models, each with about 30,000 miles of wear. Havoline 10w30 oil and
Royal Purple 5w30 oil were tested in each vehicle. The tests required about one week to
complete. They measured fuel economy and emissions of hydrocarbons, CO, and NOx.
There was no appreciable difference in the results of the fuel economy tests, but
emissions were reduced significantly when Royal Purple oil was in the vehicles.
of the EPA test are provided in this report. Typical results are presented in the Table 1.
est Oil emissions (ppm) (% ) economy
PA-75 Phase 1 Havoline 43.0 285.5 7.75 1.18 18.259
Phase 2 Havoline 5.83 34.43 0.22 0.851 16.394
Phase 3 Havoline 10.28 59.83 2.11 0.896 24.82
Havoline 13.16 116.3 7.64 1.3325 31.91
T
HC CO NOx CO2 (mpg)
E
Royal Purple 44.5 266.3 6.6 1.19 18.297
(improvement) (-3.5%) (6.7%) (14.8%)
Royal Purple 5.18 22.8 0.12 0.845 16.51
(improvement) (11.1%) (34%) (45%)
Royal Purple 10.55 48.4 1.32 0.90 24.79
(improvement) (-2.6%) (19%) (37%)
HWFET
Royal Purple 12.53 102.98 6.76 1.324 32.16
(improvement) (4.8%) (11.4%) (11.5%)
2
In a separate test, the North Carolina Highway Patrol maintained fuel consumption
also
or the
records for 25 vehicles for an extended period of time. The vehicles in this test were
4.6-liter Crown Victoria Highway Patrol Cars. Royal Purple 5w30 motor oil was
installed in the patrol cars for a period of about eleven months. The fuel economy f
eleven-month period was compared to that of a previous period in which Havoline 5w30
oil had been installed in the same vehicles. The routes and driving conditions for the two
periods were similar. The test results showed a 2.5% improvement in fuel mileage when
Royal Purple oil was in the patrol cars. Details of this test are available from Mr. Ronald
Faison of the North Carolina Highway Patrol.
he Coca-Coca bottling company in Raleigh, North Carolina installed Royal Purple
ks
80
T
motor oil in twelve of their service trucks for a period of about six months. These truc
are equipped with Caterpillar and International diesel engines. Royal Purple 15w40 oil
was compared to Kendall 15w40. Samples of the engine oil were tested at regular
intervals. The trucks were also subjected to snap acceleration smoke tests, and fuel
consumption records were kept using a computerized system. The oil sample tests
showed that the Royal Purple oil was still in good condition after a period of about 1
days. This is significant because the current maintenance policy is to drain the oil every
90 days. The fuel economy tests for the delivery trucks were inconclusive. The effects of
changes in day-to-day driving conditions obscured the limited data available. Also, no
conclusions could be drawn from the snap acceleration smoke tests. The smoke test
results were strongly dependent on the climatic conditions. The smoke levels in the
engine exhausts were greater on hot humid days than on cool clear days, and varied
greatly from one truck to another. The engine oil did not appear to have a significant
effect on emissions from these well-maintained vehicles. Details of the Coca-Cola
bottling company tests are provided in this report.
3
arefully controlled engine dynamometer tests were conducted in the Engine Research
aboratory of the Mechanical and Aerospace Engineering Department at North Carolina
rk
issions improved
hen the proprietary (Royal Purple) oil was in the research engines. Fuel consumption
C
L
State University. The tests were conducted under the direction of Professor E. M. Afify
by Jarno Kilian and Robert M. Rutherford. Three oils were tested in a single cylinder
Cooperative Lubrication Research (CLR) diesel engine, and three oils were tested in a
single cylinder CLR spark ignition engine. An engine dynamometer was employed to
obtain data at controlled operating conditions (speed and load) following SAE J 1349
engine power test code and SAE J 1312 engine performance and fuel consumption test
procedure as well as SAE exhaust emission measurement procedures for diesel and spa
ignition engines. The results of engine power output, brake specific fuel consumption,
and exhaust emissions obtained for the proprietary oil were compared with those obtained
for another synthetic oil and for the most commonly used petroleum based oil. Samples
of the oil were analyzed for wear metals and signs of degradation.
Test results from the diesel engine showed that fuel economy and em
w
was reduced by more than 3% at high engine loads. Soot, CO, and NOx emissions were
reduced by more than 10%.
4
Brake Specific Fuel Consumption Comparison
@ 1200 RPM
0.6
0.7
0.8
0.9
1
1.1
26.6112 39.9168 53.2224
BMEP (PSI)
BSFC - lb/(hr*BHp)
Shell Rotella 15w40
Amsoil 15w40
Royal Purple 15w40
CLR Gasoline Engine Fuel Economy Measurements
The test results from the CLR gasoline engine were also highly favorable towards the
proprietary oil. The Royal Purple oil improved fuel economy as indicated in the figure
above, and helped to prevent incomplete combustion and to lower NOx emissions. The
CLR engine test procedure and results are documented in this report.
Taken together, the results from the four independent tests of this work support the
following claims of the distributor of the proprietary oil. Extended oil drain intervals are
acceptable when Royal Purple oil replaces commonly used mineral oils. Fuel economy
improves by as much as 5%. Emissions of CO and NOx are reduced substantially.
5
Table of Contents
Page No.
Summary 2
Table of Contents 6
Introduction 7
EPA Tests Conducted by Independent Laboratory 10
Tests in Diesel Delivery Trucks 13
Test in Single Cylinder Diesel Research Engine 18
Tests in Single Cylinder Spark Ignition Research Engine 31
Appendix A CLR Test Definitions 40
Appendix B CLR Test Formulas 40
Appendix C ANA-LAB Oil Analysis Sheet 41
Appendix D Coca Cola Delivery Truck Oil Analysis Results 42
6
Introduction
Engine oils consist of base stocks and the various additives that are necessary to produce
satisfactory performance(1) . Refined petroleum base stocks are obtained by means of
several alternative processes. The lubricating oil stock is vacuum distilled, providing a
series of fractions of various levels of volatility and viscosity. The as-distilled base stock
fractions may contain nitrogen and sulfur compounds, metals, and aromatics that would
adversely affect stability and performance properties, and the ability of various additives
to enhance performance. The undesirable components are removed using solvents, or are
modified by hydrotreating or hydrocracking. Base stocks that are hydrotreated or
hydrocracked typically have higher percentages of saturates and reduced sulfur contents
than base stocks that are solvent refined. Hydrocracking increases the proportion of isoparaffins
in place of less desirable hydrocarbons. Waxy materials that would impede low
temperature flows are removed by means of a solvent dewaxing process, or by catalytic
dewaxing. The final properties of the refined petroleum base stocks, referred to as virgin
stocks, depend on the crude oil source and on the refining processes employed.
Synthetic base stocks are produced by chemical synthesis. Several different types of
synthetic fluids having simple composition may be produced by chemically processing
fractions from petroleum, natural gas, vegetable oil, or animal oil. A synthetic lubricant
base stock may consist of any of these fluids, or a mixture of compatible base fluids.
Blending is practiced to enhance physical properties. Some synthetic base stocks are
compatible with petroleum base stocks, and the two may be combined to form partial
synthetic blends that generally perform better than petroleum base stocks, but do not cost
as much as pure synthetic base stocks.
The additive agents in petroleum base stocks, synthetic base stocks, or partial synthetic
blends are also synthetic materials. They are used at concentration levels ranging from
several parts per million to greater than 10% by volume. Additives are designed to
protect engine surfaces, to change the oil properties, or to protect the base stocks. Engine
protectors include seal swell agents, anti-wear agents, extreme pressure agents, anti-rust
agents, corrosion inhibitors, detergents, dispersants, and friction modifiers. Oil modifiers
include pour point depressants, antifoam agents, and viscosity index improvers. Base
stock protectors include antioxidants and metal deactivators.
Engine and laboratory tests are conducted to establish the performance characteristics of
engine oils. Performance categories and classifications have been developed through the
efforts of the Alliance of Automobile Manufacturers (AAM), the American Petroleum
Institute (API), the American Society for Testing and Materials (ASTM), the Engine
Manufacturers Association (EMA), International Lubricant Standardization and Approval
Committee (ILSAC) and the Society of Automotive Engineers (SAE). The API Engine
Oil Licensing and Certification System was developed through the cooperative efforts of
AAM and API to assist engine manufacturers, oil marketers, and consumers to specify,
market, and purchase engine oils using simple designations that describe the minimum
performance standards for engine oils. Classifications of relevance to the present work
7
include the API “S” series which describes engine oil standards primarily for gasoline
engines, the API “C” series which defines standards for diesel engines, and the ILSAC
GF series, entitled Minimum Performance Standard for Passenger Car Engine Oils.
Motor oils for passenger cars and light trucks can be certified as energy conserving if
they pass a standardized ILSAC GF-3 Sequence VIB test. Energy conserving motor oils
must satisfy pass/fail criteria for fuel economy when tested against a base-line oil. The
criteria for 0w-20 and 5w-20 oils are 2.0% improvement for oils that have operated under
load for 16 hours, and 1.7% improvement for oil aged 96 hours. The criteria for 5w30
motor oils are 1.6% improvement after 16 hours of oil aging, and 1.3% after 96 hours.
In the present work, 5w30 oils are of interest for use in gasoline engines, and 15w40
oils are of interest for use in diesel engines.
All of the oils to be tested in this work are API certified. This means that they have all
been subjected to a long series of well-controlled tests in independent laboratories, and
have demonstrated that they satisfy minimum performance standards. The standards are
revised every few years to insure compatibility with the requirements of new engines.
When an API Category becomes obsolete, the oil that is certified under this category can
still be marketed, but the marketer must provide clear information indicating the product
limitations. For example, when API Category SG became obsolete, the following
statement was recommended. “This oil is rated API service category SG. It is not suitable
for use in most gasoline powered automotive engines built after 1993. It may not provide
adequate protection against the build-up of engine sludge, oxidation, or wear. “
The Royal Purple Oil Company has developed a synthetic blend motor oil that is claimed
to have performance characteristics that greatly exceed the latest minimum standards.
The oil contains an additive that is reported to have the ability to bond to bearing
materials to reduce friction and to greatly increase the oil film strength. Timkin load
capacity test results provided by the manufacturer show that the proprietary oil has five
times the load carrying capacity of conventional mineral oils. Results of severe oxidation
tests performed by the manufacturer indicate that the time to failure at high temperature is
about an order of magnitude longer than that of other synthetic oils.
The North Carolina Energy Office became interested in the proprietary oil as a possible
replacement for conventional oils used in State vehicles. They were especially interested
in the prospect of increased fuel economy and reduced emissions. Informal trial tests
performed by the North Carolina Highway Patrol had showed that the proprietary oil did
not deteriorate as rapidly as the oil already in use. Also, the proprietary oil had already
been adopted by the State of Illinois Highway Patrol, by several race-car drivers, and by
several long haul trucking firms.
Additional tests were recommended to quantify the reported advantages of the Royal
Purple oil. The proprietary oil costs more than conventional oils now being used in State
vehicles. Therefore, one-against-one tests were needed to determine whether reported
attributes such as increased fuel economy, reduced wear, longer oil drain intervals, and
8
reduced emissions would actually justify the higher initial costs. The present work was
conducted to provide data needed for the economic study.
The primary objective of the North Carolina Energy Office is energy conservation.
However, the reduction of emissions of soot, CO2, CO, and NOx is also of first
importance. The environmental impact of vehicles is a major problem that is being
addressed with increasing urgency worldwide.
Soot consists of unburned or partially oxidized fuel particles and engine oil. Soot is
especially troublesome in the exhaust of diesel engines because it will quickly clog a
conventional catalytic converter, rendering it useless. Soot also increases the wear of the
engine, especially at the exhaust valve seat. Gases leaving the combustion chamber of
diesel engines contain up to 6000 ppm of unburned hydrocarbon compounds. This
equates to the equivalent of 1-1.5% of the fuel injected. About 40% of this is unburned or
partially oxidized diesel fuel; the other 60 % is composed of partially reacted compounds
not present in the original fuel. In the atmosphere, hydrocarbon compounds acts as
irritants and odorants, and some are carcinogenic. All components except CH4 react with
other gases to form photochemical smog. Lubricating oil consumption and lube oil
particulates have been shown to be a significant contributor to diesel particulate
emissions, especially in older engines.
Carbon Dioxide is a normal final combustion product of hydrocarbon motor fuels such as
ethanol, gasoline, and diesel. CO2 is a greenhouse gas that blocks infrared radiation from
the earth’s surface and contributes to global warming. It also destroys upper level ozone.
Man-made CO2 emissions come primarily from coal burning power plants and from
vehicles. The only known way to decrease CO2 emissions from a gasoline or diesel
powered engine is to make the engine more efficient. High technology motor oils can
have a small but significant effect on engine efficiency.
Carbon Monoxide (CO) is a colorless, odorless and highly toxic gas with a density close
to that of air. It is produced by excessively rich combustion conditions in gasoline
engines, but is almost non-existent in diesel exhaust due to the diesel’s lean operation
conditions. Thus, motor oil effects on emissions of CO are more important in gasoline
engines than in diesel engines.
Oxides of Nitrogen (NO and NO2 ) are usually analyzed simultaneously in the form of
NOX. Although NOx is a relatively inactive gas in the troposphere, it is an active factor in
the destruction of stratospheric ozone. At ground level, it is a significant factor in the
creation of smog and acid rain, leading to crop damage, fish and wildlife destruction, and
building damage. NOx emissions are an important issue in the present work.
(1) SAE Handbook, Volume 1, Chapter 12, Fuels and Lubricants, Published by
Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale,
Pa. 15096.
9
EPA Tests Conducted by Independent Laboratory
Tests(2) recommended by the EPA were conducted by Perkin Elmer Automotive
Research, 5404 Bandera Rd., San Antonio,Texas. EPA 75 (city) and HFET (highway fuel
economy test) were performed using two vehicles provided by the Texas Highway Patrol.
Royal Purple 5w30 motor oil and Havoline 10w30 motor oil were tested in the vehicles.
The tests were witnessed by Mr. Ronald Faison of the North Carolina Highway Patrol,
Mr. Tom Herrmann of the Royal Purple Oil Company, and Dr. J.W. Leach of North
Carolina State University. Mr. Jerry Newbury, Manager of Fleet Operations, Texas
Department of Public Safety, provided the two 4.6 liter Ford Crown Victoria Highway
Patrol cars for the tests. The vehicles are year 2,000 models, each with about 30,000
miles of wear.
The test begins with a test preparation phase in which the test vehicle is placed on a
chassis dynamometer and driven through a prescribed sequence to simulate conditions in
a city. The vehicle is then kept in an air-conditioned building for at least 12 hours prior to
the actual test. During the actual test, the exhaust from the vehicle is caught in bags and
analyzed. The EPA 75 test consists of a cold start, and a 30-minute sequence of
accelerations and stops to simulate driving in a city. Each phase of the test must be
completed within a few seconds of a prescribed time, or the test is invalid. Also, the
instrumentation is calibrated after each phase of the test using a known sample of gases.
The instruments must measure the known sample within a prescribed tolerance, or the
test is invalid. If the EPA 75 test is successful, it is followed by the HFET test. The HFET
test is the same as the EPA 75 test, except that the test sequence simulates highway
driving.
The test vehicles were delivered to the Independent Laboratory on the morning of
October 9, 2000. The laboratory was forced to delay the start of the test by one day
because a component of the test apparatus failed. A new part was ordered from Chicago,
and was installed on the morning of Oct. 10. The oil was drained from the test vehicles
on the afternoon of October 10, 2000. New Havoline 10w30 oil and new oil filters were
installed. The vehicles were then run through the test preparation sequence and placed in
the air-conditioned environment. On the morning of Oct. 11, a Ford Crown Victoria
provided by Perkin Elmer Automotive Research was driven through the EPA 75
sequence to make sure that all of the test equipment was operating properly. The trial run
was successful. The first test vehicle, designated DPS1, was then tested. This test was
invalid because of instrumentation problems. The tests for the second test vehicle,
designated DPS2, were successful.
The Havoline oil was drained from DPS2 and replaced with Royal Purple Oil. The filter
was also changed. The vehicle was then placed on the chassis dynamometer to simulate
highway driving for 50 miles. The Royal Purple Oil was drained and replaced with new
Royal Purple Oil. The filter was also changed. The two vehicles were then subjected to
the test preparation sequence and placed in the air conditioned environment. The second
set of EPA 75 and HFET tests were successfully completed on DPS2 on October 12.
Also, DPS1 was tested successfully with Havoline oil on Oct. 12. The test of DPS1 with
10
Royal Purple oil was completed on October 14, 2000. The test results are summarized in
the tables below.
Table 1 EPA 75 and HWFET Test Results for DPS1
Test Oil emissions (ppm) (% ) economy
HC CO NOx CO2 (mpg)
EPA-75 Phase 1 Havoline 43.0 285.5 7.75 1.18 18.259
Royal Purple 44.5 266.3 6.6 1.19 18.297
(improvement) (-3.5%) (6.7%) (14.8%)
Phase 2 Havoline 5.83 34.43 0.22 0.851 16.394
Royal Purple 5.18 22.8 0.12 0.845 16.51
(improvement) (11.1%) (34%) (45%)
Phase 3 Havoline 10.28 59.83 2.11 0.896 24.82
Royal Purple 10.55 48.4 1.32 0.90 24.79
(improvement) (-2.6%) (19%) (37%)
HWFET Havoline 13.16 116.3 7.64 1.3325 31.91
Royal Purple 12.53 102.98 6.76 1.324 32.16
(improvement) (4.8%) (11.4%) (11.5%)
The total hydrocarbon and CO emissions from DPS1 were generally higher than those
from DPS2, particularly for the highway tests. The NOX emissions for DPS1 were
generally lower than those of DPS2. This would indicate that combustion is more
complete in DPS2. The engineer from Perkin Elmer stated that incomplete combustion in
DPS1 probably caused the test difficulties. However, the fuel economy results for the two
vehicles were almost identical. The results from both vehicles show that Royal Purple oil
does decrease CO emissions.
The city test CO emissions for DPS2 were reduced by more than 20%, and the highway
CO emissions were reduced by 60%. For DPS1, the city test CO emissions were reduced
by about 20%, and the highway C0 emissions were reduced by about 10% . The
hydrocarbon emissions for DPS2 were reduced by about 20% in both tests. For DPS1 the
hydrocarbon emission results are not conclusive. NOx emissions from DPS2 were also
inconclusive. For DPS1, the NOx emissions were reduced by more than 10% with Royal
Purple Oil. The Royal Purple oil did not appear to affect CO2 emissions or fuel economy
in these tests.
11
Table 2 EPA 75 and HWFET Test Results for DPS2
Test Oil emissions (ppm) (% ) economy
HC CO NOx CO2 (mpg)
EPA-75 Phase 1 Havoline 39.9 203.9 8.26 1.20 18.206
Royal Purple 33.3 160.3 6.3 1.19 18.363
(improvement) (16.5%) (21%) (24%)
Phase 2 Havoline 7.56 24.77 1.52 0.838 16.647
Royal Purple 6.16 14.12 1.31 0.843 16.608
(improvement) (18.5%) (43%) (14%)
Phase 3 Havoline 9.31 41.84 3.49 0.847 26.35
Royal Purple 8.09 31.8 4.69 0.890 25.06
(improvement) (13.1%) (24%) (-34%)
HWFET Havoline 7.29 15.42 10.02 1.35 31.68
Royal Purple 5.93 5.86 12.37 1.31 32.55
(improvement) (18.6%) (62%) (-23%)
The engineers from the independent laboratory stated that results from their tests are
repeatable within 2%. Thus, the EPA tests indicate that Royal Purple Oil does have the
ability to reduce CO and total hydrocarbon emissions.
(2) United States Environmental Protection Agency Publication EPA 420-B-98-003,
National Vehicle and Fuel Emissions Laboratory, 2565 Plymouth Rd., Ann Arbor,
MI, 48105
12
Tests in Diesel Delivery Trucks
The Royal Purple oil was installed in twelve service trucks operated by Coca Cola
Bottling Company, 2200 South Wilmington St., Raleigh NC 27603. Four of the trucks
were equipped with Caterpillar 3116 engines, and eight were equipped with International
DT-466 engines. The trucks were filled with 15-w-40 oil during May 2001, and the oil
was drained from the trucks at the end November, 2001. The three main objectives were:
1. to measure the engine wear metals in the oil over an extended period of time.
2. to determine the effect of the proprietary oil on fuel economy.
3. to measure smoke emissions in SAE J1667 snap acceleration tests.
The tests were made possible due to the cooperation of Mr. Gerry Beattie, who is the
regional fleet manager for Coca Cola, and Mr. Robert Pendergraph, who is the service
department manager at the Raleigh facility. Mr. Pendergraph collected samples of the oil
from each vehicle at regular intervals, and had the samples analyzed by two independent
laboratories. Also, a new computerized fuel tracking system was installed at the Raleigh
facility so that the fuel consumption of the twelve test vehicles could be compared to that
of other trucks in the fleet. Each vehicle was subjected to standardized SAE J1667 snap
acceleration tests in April, June, and October.
The maintenance policy at Coca-Cola Bottling Co. is to change the oil in the service
trucks every 90 days. However, to obtain data for evaluating the possibility of extended
intervals between oil changes, the proprietary oil was left in the test vehicles for about
180 days. The individual trucks were driven between 3,000 miles and 9,000 miles during
this period. The table below compares the wear elements in the last oil samples for each
truck to acceptable values published by an independent laboratory(3).
Coca-Coca Bottling Company Service Truck End of Test Wear Metal Data Summary
Truck Oil Sample Mileage Oil Wear Elements (PPM)
I.D. Engine Date at End mi. Cu Fe Cr Pb Al Si Sn
2280 3116 11/27/01 138,865 4,046 5 12 2 1 4 2 4
2289 3116 11/27/01 135,900 5,124 8 14 4 5 3 4 3
2292 3116 12/19/01 94,856 5,826 5 22 2 4 7 6 2
5783 DT466 12/19/01 60,198 3,000 7 13 0 6 4 6 1
5784 DT466 12/19/01 40,881 8,331 13 44 1 14 6 7 3
5785 DT466 12/19/01 71,814 7,367 13 61 1 14 6 7 2
6523 DT466E 12/19/01 45,977 7,075 13 39 1 9 5 7 2
6653 444E 12/19/01 70,403 5,921 11 21 0 9 4 6 2
9508 3116 12/19/01 134,302 3,025 11 24 1 6 5 6 3
11458 DT466E 12/19/01 30,747 7,130 10 29 0 8 4 9 2
11459 DT466E 12/19/01 22,000 4,886 12 27 1 8 4 6 2
11460 DT466E 12/19/02 48,042 9,245 28 47 1 10 5 9 2
Acceptable values(3) 30 145 10 20 15 25 20
(3) Ana-Lab Publication, included in Appendix C
13
The table shows that wear metals in all of the samples of oil taken at the end of the test
were within acceptable levels, and the independent laboratory indicated that the oil was
still in usable condition. Reference (1) states that wear metal levels are greatly affected
by the age of the vehicle, the operating load, driver habits, road conditions, oil filter type,
the hours and miles on the oil, and the oil type. This would explain the variations in the
data for the individual units in the table.
Truck number 11460 is the only vehicle for which a wear metal approached the published
acceptable level. After 9,245 miles, the copper wear metal level of 28 ppm in the oil
sample is near the acceptable limit of 30 ppm. However, this does not necessarily indicate
excessive wear in the engine of this vehicle. The high copper concentration in the final oil
sample from this truck is probably due to accumulations from low wear rates over an
extended period of time. The detailed test data in the appendix show that the wear rates
did not increase significantly during the final months of the test. This indicates that the oil
has not yet reached the end of its useful life.
The relatively low concentrations of wear metals in oil samples after extended drain
intervals show that the proprietary oil has done a good job of lubricating the delivery
truck engines. Test data for other oils are not available for direct comparison. The fleet
manager was reluctant to leave the standard oil in his trucks for more than 90 days. When
asked for his opinion, he stated that he believed without a doubt that the proprietary oil
does last longer than the standard oil. However, to be conservative, he would not leave
the proprietary oil in his trucks for more than 90 days on a regular basis. His personal
opinion is that the reduced wear in 90 days is not enough to justify the additional cost.
The independent laboratory analyses of the oil from the delivery trucks indicate that a
drain interval of at least 180 days is satisfactory under the present operating conditions.
This would change the economics in favor of the proprietary oil. However, the reluctance
of the experienced fleet manager to risk damage to his vehicles by extending the drain
interval is evidence that additional data may be needed.
Coca-Coca Delivery Truck Fuel Consumption Data Summary
Truck Engine Month Oil Miles Gallons Avg. Improvement
ID Type Tested Brand Traveled Consumed mi./gal.
6653 444E May Kendall 943.0 150.42 6.27
Sept. Royal Purple 748 .5 125.38 5.97 - 4.8 %
11460 DT466E May Kendall 1418 231.16 6.13
Sept. Royal Purple 1290 206.22 6.24 1.8 %
5784 DT466 May Kendall 1287 209.95 6.13
Sept. Royal Purple 1111 173.59 6.40 4.4 %
6523 DT466E May Kendall 1104 200.69 5.50
Sept. Royal Purple 854 149.71 5.70 3.6 %
14
The fuel economy tests of the delivery trucks were inconclusive. Records of fuel
consumption and truck mileage were maintained for a few weeks in May before the
proprietary oil was installed, and for the entire month of September. Problems with the
new fuel tracking system prevented the maintenance engineers from obtaining complete
records during May. As a result, direct comparisons of fuel consumption can be made for
four vehicles only. The data, which are summarized in the table above, show that fuel
economy improved by a few percentage points in three of the vehicles, and declined in
the fourth. The weekly fuel mileage averages for a given vehicle, given in the appendix,
vary by more than 10%. This indicates that day-to-day variations in loads and driving
conditions have a significant effect of fuel consumption. The total of the miles traveled
by the four vehicles during May is about 18% higher than the total for September. The
test conditions were not the same. Thus, we do not believe that any valid conclusions
regarding fuel economy can be drawn from the limited data collected during this test.
SAE J1667 snap acceleration smoke tests(4) were conducted on three separate dates to
measure the opacity of the exhaust gases from each truck. This test is used by regulatory
and enforcement authorities responsible for controlling smoke emissions from heavyduty
diesel-powered vehicles. It is a non-moving vehicle test that can be conducted along
the roadside or in a truck depot. The test is designed to identify excessive smoke
emitters, and to provide an indication of the state of maintenance and/or tampering of the
engine and fuel system. It does not replicate the federal engine certification smoke cycle.
The opacity of the exhaust gases is measured using a smoke meter that is attached to the
truck exhaust pipe. The smoke meter contains a sensor that records the strength of a light
beam that has passed through the exhaust gases. The tests of the delivery trucks were
conducted in the parking lot of the bottling company, which is about 200 ft. above sea
level. The trucks were tested late in the afternoon as they returned home from a day on
the road. Prior to the test, the truck engine was allowed to idle for several minutes until
the coolant temperature approached a steady value of about 180oF.
The actual snap acceleration test takes about 15 minutes. The truck engine idles for most
of this time period. At regular intervals, the accelerator is depressed causing the engine
speed to increase rapidly. The accelerator is then released suddenly, and smoke appears
in the exhaust gases. The smoke meter records the opacity. The test is repeated 12 times
for each truck, and the smoke meter is recalibrated for each data point. The smoke meter
employed in the tests of the delivery trucks is a CalTest 1000 model. It meets SAE J1667
technical specifications, including half-second algorithm protocols. The meter is
preprogrammed so that the SAE J1667snap acceleration test is software controlled,
eliminating user errors.
The delivery trucks were tested using the smoke meter on April 4, before the proprietary
oil was installed, and the tests were repeated on June 13 and October 3. The average
opacity values recorded for each test are summarized in the table below. Opacity is
defined as the percentage of light transmitted from a source that is prevented from
reaching a light detector. Most of the States now permit(5) opacity values to 40% for
vehicles manufactured after 1990, and opacity values to 50% for vehicles manufactured
15
prior to 1991. Cut points in high altitude States may be greater than this. The table shows
that the measured smoke levels in the delivery truck exhausts were relatively low, and
varied by only a few percentage points throughout the test period.
A previous test involving 24 diesel-powered vehicles in California (4) showed that
ambient conditions have a large effect on as-measured snap acceleration smoke results.
Eight tests were conducted on each of the 24 vehicles at six different elevations. Post-test
analyses indicate that dry air density is the most important variable. However, engines
with different combustion and smoke control technologies had different degrees of
sensitivity to changes in air density.
The small differences in opacity measurements in the present work are probably due to
variations in ambient conditions on different test days, and not to the effects of the engine
oil. The opacity measurements for 6/13/01 are generally higher than those for the other
two test days. This is certainly not an engine oil effect, because the same oil was in the
trucks for two of the test days. However, the dry air density was lower during the summer
day than in the Spring or Fall. Overall, the smoke levels increased slightly for some
trucks, and decreased for others. The data indicates that the engine oil does not have a
large effect on smoke levels in snap acceleration tests for well-maintained trucks. This
test does not appear to have any relevance in the present work.
Coca-Cola Bottling Company Snap Acceleration Smoke Test Data Summary
Truck Test Date, 4/4/01 Test Date, 6/13/01 Test Date, 10/3/01
I.D. Engine mileage opacity mileage opacity mileage opacity
2280 3116 134,001 1.3 135,405 1.3 137,737 2.6
2289 3116 129,972 3.0 131,750 4.6 134,398 6.3
2292 3116 87,708 1.5 90,185 1.6 94,061 3.8
5783 DT466 56,603 11.2 57,777 16.1 59,402 8.9
5784 DT466 31,258 9.0 34,443 5.3 truck unavailable
5785 DT466 62,990 2.6 65,557 4.2 69,776 6.0
6523 DT466E 37,597 15.8 40,250 12.0 44,881 7.4
6653 444E 63,046 2.6 65,660 6.3 69,287 5.4
9508 3116 130,647 12.5 131,920 22.3 134,173 14.5
11458 DT466E 22,124 4.7 25,220 6.9 29,782 7.3
11459 DT466E 15,981 4.8 17,845 5.6 20,978 7.7
11460 DT466E 36,823 4.1 41,111 6.1 47,562 7.1
(4) “Society of Automotive Engineers (SAE) J1667 Recommended Practice, Snap
Acceleration Smoke Test Procedure for Heavy-Duty Powered Vehicles,” Available from
SAE Publications, 400 Commonwealth Dr., Warrendale, PA, Feb. 1996.
(5)”Establishment of Smoke Opacity Cut Points for SAE J166,“ EPA Cooperative
Research Program, Gary W. Pollak, Program Manager, Available from SAE
Publications, 400 Commonwealth Dr., Warrendale, Pa, Nov. 1998
16
17
Single Cylinder Diesel Research Engine Tests
This section documents tests conducted at the North Carolina State University using a
CLR research engine designed for oil tests. Shell Rotella 15w40 petroleum based oil,
Amsoil 15w40 synthetic based oil, and Royal Purple 15w40 synthetic blend oil were
tested in the engine.
All three of the oils are certified through the American Petroleum Institute (API) Engine
Oil Licensing and Certification System (EOLCS). This is a voluntary licensing and
certification program that authorizes engine oil marketers who meet API requirements to
use the API Marks on their containers. Motor oils meeting the API requirements are
recommended by vehicle manufacturers. Performance requirements, test methods, and
pass/fail limits are cooperatively established by engine manufacturers, and by technical
societies such as the Society of Automotive Engineers (SAE) and the American Society
for Testing and Materials (ASTM). The EOLCS is backed by an on-going monitoring and
enforcement program. Additionally, the program ensures that the API registered symbols
are properly displayed on containers and convey accurate information to consumers.
Since the oils tested herein are already certified for use in diesel engines, the present
work is not meant to check the oils’ ability to meet engine manufacturer’s requirements,
but to quantify differences in fuel consumption, emissions and engine wear. The goal of
the present work is to determine whether high performance oils are worth the additional
cost. The high initial cost can be justified if the oil substantially reduces emissions,
improves fuel economy, reduces wear, or lasts longer
Since motor oil is one of the few regular maintenance items on a diesel engine, it plays a
significant part in determining the operating cost of the engine by affecting engine
durability and fuel consumption. Additionally, new regulations require diesel engines to
have reduced emissions, which can also be affected by the composition of the motor oil.
Over the last two decades, synthetic motor oil usage has become more widespread, and
synthetic oil marketers claim that there are substantial improvements in the areas of:
• High shear stability
• Corrosion prevention
• Improved fuel economy
• Reduced oxidation
• Extended drain intervals
• Reduced oil consumption
• Reduced emissions
These attributes are mentioned by Royal Purple and by Amsoil as arguments for
purchasing their respective synthetic oils.
18
Research Project Equipment
Diesel Engine
The research was performed on a Laboratory Equipment Corp. (Labeco) CLR engine,
which is a high speed four stoke designed primarily for oil test and research work. The
CLR is a single cylinder engine with a bore and stroke of 3.8125” x 3.750” respectively.
The displacement is 42.5 cu. in. and has a compression ratio of 16.7:1. The oil sump
holds between 2-4 pints, and the oil pressure is adjustable. The engine is water-cooled
and is of the “Mexican Hat” bowel-in-piston type. The engine is fed by a Bosch APE1B
diesel pump which allows the diesel injection timing to be adjusted while the engine is
running so that various injection phenomenon can be studied. Adjustments in the amount
of fuel delivery per stroke at varying load and speed are made by rotating the pump
plunger in its barrel. The diesel pump is driven by the diesel engine’s cam shaft. The
throttle setting is adjusted manually with micrometer style readout.
Before testing began, the engine was completely torn down and rebuilt to “as-new”
specifications with a new piston, cylinder sleeve, all new bearings, new valves and new
valve oil seals. The engine was then broken in accordance with the LABECO instruction
manual before the oil testing started. The variable fuel injecting timing mechanism was
19
locked for this research to insure consistent injection timing over the course of the
research. The diesel pump and injector were also rebuilt and calibrated before testing .
• Dynamometer
The engine load is measured using an Eaton Eddy Current dynamometer, the rotor of
which is coupled to the engine crankshaft. The dynamometer lever arm is designed so
that it impresses force on an Emery AD-1 hydraulic load cell when the dynamometer
housing tries to rotate. The housing will tend to rotate due to an induced electromotive
force between the moving rotor and the housing itself. Eddy currents are generated in the
metal rotor as it turns in the magnetic field created by the variable supplied voltage.
These currents cause a force to be developed between the rotor and the dynamometer
housing, imposing a load on the engine. The hydraulic load cell is connected to a boron
tube/needle indicator, which displays the amount of load applied to the engine in pounds.
The dynamometer is calibrated before testing begins. It is controlled by an Eaton Mark
III solid-state controller. This system uses feedback, or closed loops to linearize and
stabilize its performance characteristics. This assures highly accurate load application to
the engine even over hours of use. From the torque measurement and the engine speed
the power produced by the engine can be calculated. It is then converted to brake mean
effective pressure (BMEP) and used for the analysis of the oil’s performance in terms of
emissions and fuel consumption.
• Instrumentation
The instrumentation of the engine includes the following:
- Calibrated Electronic Tachometer with 10RPM graduations
- Manometer displaying the mass airflow into the engine
- Dynamometer load cell readout
- Dynamometer adjustment and status displays
- Oil Pressure
- Crankcase Vacuum
- Multi-channel thermocouple readout for measuring:
- Engine water inlet temperature
- Engine water outlet temperature
- Crankcase oil temperature
- Ambient air temperature
- Exhaust gas temperature
- Fuel consumption timer
Emissions Analyzer
Engine exhaust emissions are tested by the use of a Nova Analytical Systems Inc.
Autocheck Model 975 Exhaust Emission Analyzer. The Autocheck 975 is the latest,
state-of-the-art portable engine exhaust analyzer that uses non-dispersive infra red
20
(NDIR) detector technology to determine CO, CO2
and HC concentrations. Oxygen is detected by long
life electrochemical sensors. The analyzer allows for
continuous measurement of CO, CO2, HC, O2 and
NOx gasses. The internal sensors are approved by
world recognized EPA ASM, AMS/BAR97 and
OIML CLASS 0&1 tests. The sensors were replaced
at the beginning of the project and are guaranteed to perform for two years from the date
of installation. The analyzer was calibrated before each of the tests began using National
Welders Research Grade custom gases.
Soot Level Meter
A CalTest 1000 Smokemeter was used, which meets SAE J1667
technical specifications, including 1/2 second algorithm p
The meter’s preprogrammed SAE J1667 snap-acceleration
software controlled, eliminating user errors. It was used in
conjunction with a soot sight box that was custom built for
laboratory testing where an open tailpipe is undesirable.
rotocols.
test is
The smoke meter was used in the
research laboratory through the use of a
custom portal consisting of two view
ports made of laboratory grade boron
glass. The glass was kept clean by having
compressed air between the exhaust gas
and the view port, effectively shielding it
against deposits. The setup is shown in
the picture to the right.
Fuel Consumption Timer
Specifically for this research, a device was built that measures the time it takes for the
diesel engine to consume 100 ml of No. 2 diesel fuel. It consists of a graduated cylinder
that is filled with the diesel. A float, equipped with a magnet triggers two reed switches,
one at the beginning of the 100 ml run and one at the end of the 100 ml run. The accuracy
of the device was within SAE tolerances ( 3% maximum) at 2.3% repeatability.
21
Development of Testing Protocols
Several SAE Test standards were used to create a test that is meant to be more realistic in
terms of real-world application of results to road-going vehicles. The foundation is the
SAE J304 diesel test standard, which was specifically written for the L-38 test engine.
The SAE J1349 and SAE J1995 Engine Power Test Codes were incorporated into the
J304 protocol. The testing procedure is outlined in a later section. Soot Testing was done
in accordance with the SAE J255a Diesel Engine Smoke Measurement. Special attention
was paid to the tolerances on engine RPM and repeatability of fuel consumption
measurement data.
Research Tolerances
Engine Speed: ± 10 RPM
Difference in coolant temperature ± 2 oF
Oil Pressure ± 2 PSI
Crankcase vacuum 3 ± 0.5” H2O
Specific humidity ± 2%
Water temp from head 160 ± 5 oF
Engine Oil Temp 180 ± 5 oF
Single Cylinder Diesel Testing
Procedure Developed and Used
22
Clean out emissions analyzer line with compressed air with analyzer disconnected
Clean view ports on soot box with Windex and lint-free tissue
Check engine oil level
Check accessory case oil level
Check dynamometer bearing oil level
Check vacuum pump oil level
Check that exhaust system valve is turned off
Replace cotton pre-filters in exhaust measurement system
Check that the final filter on the emissions tester is not contaminated
Fill fuel measurement cylinder with diesel
Turn water supply on, allow pressure to build in expansion tank
Turn engine exhaust stack fan on
Turn on soot box air supply, make sure that at least 80 PSI static air pressure is
available
Check that dynamometer excitation is turned to zero
Energize all electrical systems, including dynamometer power
Adjust water level in coolant tower to center mark
Turn on battery charger
Turn on crank case vacuum pump, allow vacuum to start building on gage
Start engine
Adjust crankcase vacuum for 4 inches water on gage
Allow to run at no-load for 5 minutes at 1000 RPM
Turn off battery charger
Over next 25 minutes, gradually increase excitation and engine speed to speed
required for testing
For 30 minutes, run engine at test load and speed to reach steady state
Check water level in cooling tower
Make sure that the engine temperature is stable for 5 minutes before beginning testing
Take soot, emissions and fuel consumption measurements at two different RPM
settings and three different loads (we used 1200, 1600 RPM and 10,15 and 20 lb. of
load)
When switching between loads, wait 15 minutes for the engine temperatures to reach
steady state
When switching between Rpm’s, wait 30 minutes for the engine to reach steady state.
Fuel Measurement:
Measure time taken for engine to use 100ml of BP No.2 Diesel Fuel
Taken with stopwatch between marks on graduated cylinder
Maintain engine RPM within 10 RPM during test
Soot Measurement
Complies with SAE J1667 Snap Test
Turn meter on with sensor raised above soot box
Follow instructions on screen
Maintain engine RPM within 10 RPM during test
Emissions Measurement
23
Make sure exhaust system valve is closed
Disconnect the line at the meter
Turn emissions meter on, allow meter to complete zero span calibration
Reconnect line
Start emissions testing, open exhaust system valve
Make sure that there is 2.0 SCFH of flow through the meter. If not, a filter is
clogged, if too high, adjust with valve
Maintain engine RPM within 10 RPM during test
Meter beeps when test is complete, print out the results
Close exhaust system valve
After testing is complete, run engine at no load for 10 minutes to allow to cool down
Stop engine
Turn off all electrical devices
Turn off exhaust stack fan
Turn off soot box air supply
Turn off water supply
Enter data in spreadsheet templates on computer
Data Summary for the three oils tested in the Labeco Research Diesel Engine
1) Fuel Consumption Comparison Summary:
Brake Specific Fuel Consumption Comparison
@ 1200 RPM
0.6
0.65
0.7
0.75
0.8
0.85
0.9
26.6112 39.9168 53.2224
BMEP (PSI)
BSFC -
lb/(hr*BHp)
Shell Rotella 15w40
Amsoil 15w40
Royal Purple 15w40
At each load level, the Royal Purple showed significantly lower fuel consumption than
either the Amsoil or Shell. At 1200 RPM, the greatest improvement of the Royal Purple
oil was over Amsoil with a fuel consumption reduction of 3.37%. The next greatest
improvement was against Shell Rotella with a 3.68% improvement. These were both
achieved at a BMEP of 53.2224 PSI, which corresponds to a 20lb load.
24
Brake Specific Fuel Consumption Comparison
@ 1600 RPM
0.85
0.9
0.95
1
1.05
1.1
1.15
26.6112 39.9168 53.2224
BMEP (PSI)
BSFC - lb/(hr*BHp)
Shell Rotella 15w40
Amsoil 15w40
Royal Purple 15w40
The Royal Purple results at 1600 RPM again indicated lower fuel consumption than
either Shell or Amsoil. The greatest improvement of the Royal Purple oil was over Shell
Rotella with a fuel consumption reduction of 2.48%. The next greatest improvement was
against Amsoil with a 1.48 % improvement. These were both achieved at a BMEP of
53.2224 PSI, which corresponds to a 20lb load.
2) Soot Generation Analysis Summary
1200 RPM Soot C omparison
21
22
23
24
25
26
27
28
29
25 30 35 40 45 50 55
BM EP (PSI)
Soot Percentage (%)
S he ll Ro te lla 1 5 -4 0
Amsoil 15w40
Ro ya l P urp le 1 5W-4 0
At 1200 RPM, the Royal Purple oil performed better at all loads than the other two oils,
especially at high load. The greatest soot reduction was against Shell Rotella with a
decrease in soot generation of 11.75% at a BMEP of 53.2224 PSI.
25
1600 RPM Soot Comparison
21
23
25
27
29
31
33
35
37
25 30 35 40 45 50 55
BM EP (PSI)
Soot Percentage (%)
She ll Rotella 15-40
Amsoil 15W -40
Royal P urp le 15w40
At 1600 RPM, the Royal Purple oil performed better at all loads than the other two oils,
again especially at high load. The greatest soot reduction was against Shell Rotella
with a decrease in soot generation of 17.58 % at a BMEP of 53.2224 PSI.
3) NOx Generation Summary
1200 RPM NOx Comparison
350
400
450
500
550
600
650
700
25 30 35 40 45 50 55
BM EP (PSI)
NOx (parts per million)
S hell Rotella 15-40
Amsoil 15W -40
Royal P urple 15w40
At 1200 RPM, there was a significant reduction in NOx emissions of the Royal Purple
compared to both the Shell and Amsoil lubricants. The highest reduction in NOx
emissions was between Royal Purple and Amsoil, with Royal Purple tests showing an
average NOx production that is 12.06% lower than that of the Amsoil tests.
26
1600 RPM NOx Comparison
290
340
390
440
490
25 30 35 40 45 50 55
BM EP (PSI)
NOx (parts per million)
She ll Rotella 15-40
Amsoil 15w40
Royal P urple 15w40
At 1600 RPM, the results are more varied, with Shell Rotella having the lowest NOx
levels at high loads. Royal Purple still had lower NOx emissions than Amsoil.
4) CO Generation Summary
1200 RPM CO C omparison
0.07
0.12
0.17
0.22
0.27
0.32
0.37
0.42
25 30 35 40 45 50 55
BM EP (PSI)
CO Percentage (%)
S hell Rotella 15-40
Amsoil 15w40
Royal P urp le 15w40
At 1200 RPM, the amount of carbon monoxide produced at any load was lowest with the
Royal Purple Oil. The greatest reduction was at a BMEP of 53.2224 PSI, which
corresponds to a 20lb load. Between Amsoil and Royal Purple, the emissions reduction
was 28.15 %.
27
1600 R PM C O C omparison
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
25 30 35 40 45 50 55
BM EP (PSI)
CO Percentage (%)
S he ll R o te lla 1 5 -4 0
Amsoil 15w40
Ro ya l P urple 15w40
CO emissions at 1600 RPM were again lowest in the Royal Purple tests. The greatest
reduction was over Amsoil with a decrease of 33.87 % in CO emissions.
Soot Level Statistical Analysis Results
he analysis shows that speed, load, and oil tested all had a significant effect on soot
he
ot
production is still significant as the p-value is less than .05 (.0185).
Source df SS MS F p-val
Oil 2 14.75180 7.37590 12.69490 0.018524000
Speed 1 21.67450 21.67450 37.30460 0.003637000
Load 2 164.35660 82.17830 141.43910 0.000194410
Oil*Speed 2 0.55517 0.27759 0.47776 0.651540000
Oil*Load 4 12.53290 3.13320 5.39270 0.065755000
Speed*Load 2 20.55020 10.27510 17.68470 0.010323000
Error 4 2.32410 0.58102
R-square 0.99018
Standard Error 0.76224
Sequential Sums of Squares ANOVA Table
T
production. Load was the factor with the greatest effect, then speed, and finally oil. T
three were separated by a factor of ten each. The separation between oils indicated in the
means analysis showed that Shell produced the most soot (26.6%), followed by Amsoil
(25.17%) and Royal Purple (24.5%) respectively. While this effect was greatly
overshadowed by the effect of speed and load, the interaction between oil and so
28
Oil Sample Data
Viscosity
Fuel
Dilution Soot Oxidation Nitration
Water
%
Antifreeze
%
Sample
0138 ew Shell 0 0 14 N 14.4 0 0 0 0
Sample
140139
New
Amsoil 14.8 0 0 0 0 0 0
Sample
140140 New Royal 14.1 0 0 0 0 0 0
Sample
140141 sed Shell 14.9 0 0 0 0 0 0 U
Sample
140142
Used
Amsoil 14.3 0 0 0 0 0 0
Sample
140143
Used
Royal 14 0 0 0 0 0 0
Figure 2A - Oil Condition
Silicon Iron Chromium Aluminum Copper Lead Tin Nickel Silve
Sample
0138 ew Shell 14 N 5 2 0 2 0 0 0 0
Sample
140139
New
Amsoil 3 3 0 2 0 1 0 0
Sample
140140
New
Royal 3 2 0 2 0 1 0 0
Sample
140141 hell 9 6 0 2 0 3 0 0
Used
S
Sample
140142
Used
Amsoil 5 5 0 2 0 1 0 0
Sample
140143
Used
Royal 5 4 0 2 0 0 0 0
Figure 2B - Wear Materials
29
Molybdenum Magnesium Sodium Titanium Boron Potassium Calcium Zinc Barium Phosphorus
Sample
140138
New
Shell 0 18 5 0 301 10 2573 1316 0 1384
Sample
140139
New
Amsoil 0 19 4 0 1 0 3504 1279 0 1328
Sample
140140
New
Royal 131 11 3 0 1 4 2531 1116 0 1261
Sample
140141
Used
Shell 0 16 5 0 264 8 2182 1125 0 1311
Sample
140142
Used
Amsoil 0 16 8 0 7 2 3427 1275 0 1231
Sample
140143
Used
Royal 134 9 4 0 1 5 2715 1138 0 1195
Figure 2C - Additive Packages
Oil Sample Analysis
en designed to use up engine oil while operating, requiring a
ontinuous input of fresh oil. Most of the oil seeped past the rings and was burned in the
e
tor oils used in the early years,
nd now has complex additive packages for maximum performance and minimum wear.
2. Oxidation inhibitors
ant
ex improvers
The here is decreased wear for all materials for the Royal
urple brand motor oil. As can be seen from the above data, there was no contamination
Early engines were oft
c
engine. This led to the need for frequent oil changes due to the contamination of the
remaining oil due to blow-by. In early engines the rule was to change the crankcase oil
every 1000 miles. Modern engines have closer tolerances, run hotter and must operat
longer between oil changes. Also, they have to operate over large ambient temperature
ranges since seasonal oil changes are no longer necessary. Many engine manufacturers
now recommend oil changes ever 6000 miles or more.
Modern motor oil is substantially different from the cas
a
These additives include:
1. Antifoam agents
3. Pour-point depress
4. Antirust agents
5. Detergents
6. Antiwear agents
7. Viscosity ind
returned oil samples show that t
P
in terms of water, soot or fuel in the oil samples, indicating that the engine stayed well
within specifications throughout all testing.
30
Single Cylinder Gasoline Research Engine Tests
This section docum ersity using a
LR gasoline engine designed for oil testing. Shell Formula 5w30 petroleum based oil,
e
t
• Gasoline Engine
e search was performed on a Laboratory Equipment Corp. (Labeco)
LR engine, which is a high speed four stoke designed primarily for oil test and research
ents tests conducted at the North Carolina State Univ
C
Amsoil 5w30 synthetic based oil, and Royal Purple synthetic oil with Synerlec additiv
were tested in the engine under identical conditions. The oils were tested with the engine
operating at 1200 rpm and at 1600 rpm. The engine was loaded by means of a brake on
the dynamometer, and the throttle was opened until the engine maintained the desired
speed. Light engine loads, medium engine loads, and heavy engine loads were simulated
at each rpm by adjusting the brake and the throttle valve. Fuel consumption and exhaus
gas compositions were recorded at each load.
Research Project Equipment Continued
Th gasoline engine re
C
work. The CLR is a single cylinder engine with a bore and stroke of 3.8125” x 3.750”
respectively. The displacement is 42.5 cu. in. and has a compression ratio of 9:1 and was
run on 87 octane unleaded gasoline. The oil sump holds between 2-4 pts., and the oil
31
pressure is adjustable. The engine is water-cooled and fuel is metered through a Stomberg
carburetor. The throttle adjustment is made through a screw mechanism that is locked
constant RPM research. Before testing began, the engine was completely torn down an
rebuilt to “as-new” specifications with a new piston, cylinder sleeve, all new bearings,
new valves and new valve oil seals. The engine was then broken in accordance with the
LABECO instruction manual before the oil testing started. The carburetor was also
completely rebuilt before testing began.
for
turnbuckle and lock nut were used to set the engine speed for the gasoline testing. This
sulted in very accurate control of engine RPM. There were no variations in the RPMs
ingle Cylinder Gasoline Testing Procedure Developed and Used
er disconnected
Check engine oil level
aring oil level
ed off
aust measurement system
er is not contaminated
Gasoline Throttle Control Explained
A
re
since two springs were employed to remove any play in the throttle linkage.
S
Clean out emissions analyzer line with compressed air with analyz
Check accessory case oil level
Check dynamometer be
Check vacuum pump oil level
Check that exhaust system valve is turn
Replace cotton pre-filters in exh
Check that the final filter on the emissions test
Fill fuel measurement cylinder with 87-octane gasoline
32
Turn water supply on, allow pressure to build in expansion tank
Turn engine exhaust stack fan on
Check that dynamometer excitation is turned to zero
Energize all electrical systems, including dynamometer power
start building on gage
at no-load for 5 minutes at 600 RPM
and engine speed to speed
cooling tower
ginning testing
n measurements at two different RPM settings
ement:
engine RPM within 10 RPM during test
meter
mplete zero span calibration
here is 2.0 SCFH of flow through the meter. If not, a filter is clogged,
lete, print out the results
inutes to allow to cool down
ust stack fan
mplates on computer
ngine Oil Test Project Results Summary and Discussion
Adjust water level in coolant tower to center mark
Turn on battery charger
Turn on crank case vacuum pump, allow vacuum to
Start engine
Adjust crankcase vacuum for 4 inches water on gage
Allow to run
Turn off battery charger
Over next 25 minutes, gradually increase excitation
required for testing
For 30 minutes, run engine at test load and speed to reach steady state
Check water level in
Make sure that the engine temperature is stable for 5 minutes before be
Take emissions and fuel consumptio
and three different loads (we used 1200, 1600 RPM and 10,15 and 20 lb. of load)
When switching between loads, wait 15 minutes for the engine temperatures to reach
steady state
When switching between RPM’s, wait 30 minutes for the engine to reach steady state.
Fuel Measur
Measure time taken for engine to use 100ml of BP 87-octane regular unleaded
gasoline
Taken with stopwatch between marks on graduated cylinder
Maintain
Emissions Measurement
Make sure exhaust system valve is closed
Disconnect the line at the
Turn emissions meter on, allow meter to co
Reconnect line
Start emissions testing, open exhaust system valve
Make sure that t
if too high, adjust with valve
Maintain engine RPM within 10 RPM of target speed during test
Meter beeps when test is comp
Close exhaust system valve
After testing is complete, run engine at no load for 10 m
Stop engine
Turn off all electrical devices
Turn off exha
Turn off water supply
Enter data in spreadsheet te
Gasoline Single Cylinder E
33
Data Summary for the three oils tested in the Labeco Research Gasoline Engine
1.) Fuel Consumption Comparison
The experimental data presented in the figures below show that Royal Purple oil required
less ads than the other two oils at all of the engine
m
fuel to satisfy the imposed engine lo
loads and engine speeds tested. At 1200 rpm, Royal Purple oil was about 4.5% more fuel
efficient than Shell Formula oil, and about 2.5% more efficient than Amsoil. At 1600 rp
the Royal Purple oil required about 5% less fuel
