Lab--Wear Check, So. Carolina
Vehicle--Subaru Legacy Outback, '02
Engine--2.5l boxer 4 cyl., non-turbo; oil capacity with Baldwin filter is 4.4 qts.
Oil--Chevron Supreme 5W-30 SL.
Additive--Tribomaxx: calcium sulfate which, I believe, is a surfactant, with a good charge of sodium.
OCI--8800 miles.
Filters-- 1. Purolator Premium Plus, 3300 mi.;
2. Baldwin, 5500 mi.
Top-up oil: 0 qts. needed at filter change at 3300 miles, but added about 26 oz. at filter change because some oil stayed in the old filter and also the Baldwin filter is about 6 oz. larger in capacity than the Purolator PP. This 26 oz. of added lubricant included .6 oz. of the Tribomaxx to go with the "top-up" oil. No top-up oil needed at 8800 if I had decided to continue the OCI.
Driving conditions--60:40 in-town:highway; last 1500 miles were pretty much winter driving in town, e.g., 15F to 40F, snow, ice, etc.
The other items that jumped more than they should have are: sulfation =167, should have been 153 if the sulfation rate at 3300 miles maintained throughout the last 5500 miles; likewise, nitration jumped from 45 to 175. It should have been 115, all things being equal.
I was happy with the fact the potassium burned off through the second stage of the OCI. That which registered in the first analysis was residue from a head gasket issue I had prior to the oil change preceding these 2 samples. The head gasket was replaced on warranty at about 37,000 miles.
I did run this oil 1800 miles more than I should have, even with the additive. I'll keep my OCIs to 5000 to 7000 miles from now on. Despite the analysis results and the recommendation that it could go longer, the oil felt tired to me during the last 1000 miles. Highway mileage went down a bit, maybe due to a dirty air filter -- and possibly the viscosity increase. Engine idle wasn't quite as smooth, and the engine ran a little noisier at high rpms, e.g., when in passing gear.
The cost of the oil is $1.14/qt. from Costco -- up 3 cents from 6 months ago -- and $.50/qt for the Tribomaxx at .5 oz./qt. Total = $1.64/qt. Sure beats the prices of the synthetics, and maybe even some of the performances.
Another point is that this Chevron 5W-30 was the SL, not the SM. We can see that the SL works well with the Tribomaxx, but I'll have to do this again with the SM to see if SM and Tribomaxx are compementary.
The TBN looks pretty good after 8800 miles. That's the Tribomaxx at work.
Any other thoughts?
[ January 04, 2006, 01:24 AM: Message edited by: 59 Vetteman ]
Vehicle--Subaru Legacy Outback, '02
Engine--2.5l boxer 4 cyl., non-turbo; oil capacity with Baldwin filter is 4.4 qts.
Oil--Chevron Supreme 5W-30 SL.
Additive--Tribomaxx: calcium sulfate which, I believe, is a surfactant, with a good charge of sodium.
OCI--8800 miles.
Filters-- 1. Purolator Premium Plus, 3300 mi.;
2. Baldwin, 5500 mi.
Top-up oil: 0 qts. needed at filter change at 3300 miles, but added about 26 oz. at filter change because some oil stayed in the old filter and also the Baldwin filter is about 6 oz. larger in capacity than the Purolator PP. This 26 oz. of added lubricant included .6 oz. of the Tribomaxx to go with the "top-up" oil. No top-up oil needed at 8800 if I had decided to continue the OCI.
Driving conditions--60:40 in-town:highway; last 1500 miles were pretty much winter driving in town, e.g., 15F to 40F, snow, ice, etc.
Almost all of the metals showed wear at the same rates when comparing the 3300 mile sample with the 8800 mile sample. Aluminum was the one which jumped more than it should have. Might be due to the jump in silicon as well. Time to change the air filter.code:
Sample Dates 07/28/05; 12/17/05
Silicon 2.1; 11
Potassium 2.6; 0.0
Sodium 83; 78 (the addit.)
Fuel %
Glycol 0.12; ---
Water %
Soot % 0; 0
Sulfation 60; 167
Nitration 45; 175
OIL CONDITION
Sample Date 07/28/05; 12/17/05
Boron 78; 39
Barium 0.7; 0.0
Calcium 3820; 3254
Magnesium 5.2; 9.6
Molybdenum 71; 61
Sodium 83; 78
Phosphorus 694; 714
Sulfur 3284; 3554
Zinc 764; 784
Visc@40°C ---; ---
Visc@100°C 9.83; 10.7
Oxidation 55; 130
TAN ---; ---
TBN 9.63; 5.18
WEAR
Sample Date 07/28/05; 12/17/05
Iron 3.7; 8.3
Nickel 0.6; 0.6
Chromium 0.2; 0.5
Titanium 0.0; 0.1
Copper 2.5; 6.0
Tin 0.3; 0.0
Lead 1.4; 2.3
Silver 0.0; 0.0
Aluminum 0.8; 4.9
The other items that jumped more than they should have are: sulfation =167, should have been 153 if the sulfation rate at 3300 miles maintained throughout the last 5500 miles; likewise, nitration jumped from 45 to 175. It should have been 115, all things being equal.
I was happy with the fact the potassium burned off through the second stage of the OCI. That which registered in the first analysis was residue from a head gasket issue I had prior to the oil change preceding these 2 samples. The head gasket was replaced on warranty at about 37,000 miles.
I did run this oil 1800 miles more than I should have, even with the additive. I'll keep my OCIs to 5000 to 7000 miles from now on. Despite the analysis results and the recommendation that it could go longer, the oil felt tired to me during the last 1000 miles. Highway mileage went down a bit, maybe due to a dirty air filter -- and possibly the viscosity increase. Engine idle wasn't quite as smooth, and the engine ran a little noisier at high rpms, e.g., when in passing gear.
The cost of the oil is $1.14/qt. from Costco -- up 3 cents from 6 months ago -- and $.50/qt for the Tribomaxx at .5 oz./qt. Total = $1.64/qt. Sure beats the prices of the synthetics, and maybe even some of the performances.
Another point is that this Chevron 5W-30 was the SL, not the SM. We can see that the SL works well with the Tribomaxx, but I'll have to do this again with the SM to see if SM and Tribomaxx are compementary.
The TBN looks pretty good after 8800 miles. That's the Tribomaxx at work.
Any other thoughts?
[ January 04, 2006, 01:24 AM: Message edited by: 59 Vetteman ]