Straight weight oil tests

[JHZR2]

Hi,

What is the difference between tests for a straight weight oil and one for a multigrade?

For example, Amsoil ACD qualifies as both a 30 wt straight oil, as well as a 10w30 multi.

I can understand how it is tested as a multigrade - with a test at 100 and a cranking test at -30 or 35, whatever the spec is...

But is a 'straight' weight oil one that simply has no VIIs and is ONLY tested at 100C? Or is there some second test thatis performed all the same?

Any info would be appreciated.

Thanks!

JMH

 

[bruce381]

you could sell a multi as a straight wt I guess but why?? do not understand question.
bruce

 

[JHZR2]

There is some standard battery of tests that is used to determine what 'weights' an oil is... Amsoil sells its ACD diesel oil as qualifying as both a straight 30 wt and as a multigrade oil... it has no VIIs and a diesel add pack.

So I have to wonder what tests are used to quantify the 'weight' of a straight weight oil... Amsoil may do none, and just make the claim that it is a 'striaght' 30wt oil because it has no VIIs... or else it might be tested to be qualified as that... I am not sure.

And so I dont know if there even is a qualifying test for straight weight oils, other than their viscosity at 100C.

Thus my question.

JMH

 

[KW]

Great question, I have wondered about this myself.

 

[bruce381]

Ok straight wt needs only Vis at 100C.
Thats it.

It is harder to meet multi specs than straight wt.

Straight wt needs no COLD end tests and is cheaper to make. Only Vis at 100C.

Multi needs Vis at 100C and Cold crank and also
HTHS a high temp oil shear viscosity test to qualify.

A multi is more costly to make so is foolish to sell a multi as ONLY a straight wt tho you can.

Some or all syns will meet multi specs with out much additional cost and can be sold as both if the MFG wants to.

bruce

 

[JHZR2]

Got it... well, I guess Amsoil sees it as a marketing point to list it as both, by virtue of the fact that it contains no VIIs... I like it in my lawn equipment and might use it elsewhere too! Per their site for product ACD:

PRODUCT DESCRIPTION
AMSOIL Synthetic 10w30/SAE 30 Diesel Oil (ACD) is formulated with premium synthetic base oils that exceed both 10w30 multi-grade and SAE 30 straight-grade viscosity requirements for outstanding performance in modern and older diesel engines.
Unlike conventional SAE 30 motor oils, AMSOIL ACD has a naturally high viscosity index and does not contain paraffin (wax).
It has a -36°F pour point and qualifies for SAE 10W, making it an “all season” multi-grade lubricant with a wide operating temperature range.
AMSOIL ACD is formulated without viscosity index improvers (VI). ...
Where these viscosity grades are specified, AMSOIL Synthetic 10w30/SAE 30 Diesel Oil (ACD) provides outstanding performance
as a straight-grade SAE 30 for older two- and four-stroke diesels and as a multi-grade SAE 10w30 in modern four-stroke diesels as well as gasoline engines.

• SAE 10w30 performance without VI improvers
• Cost-effective replacement for conventional oils
• Excellent shear stability
• Outstanding wear protection
• Superior protection over a broad range of operating temperatures
• Extended service life with oil analysis

PERFORMANCE
AMSOIL ACD is recommended for diesel engines and other applications requiring any of the
listed worldwide specifications and gasoline engines requiring API SL, SJ, SH... or ACEA A3.

• API CI-4+/CH-4/CG-4/SL
• ACEA A3/B3, E2, E3, E5

• Mercedes Benz 229.1

SERVICE LIFE

Personal Light Truck Diesel Engine Service

• Normal Service(3) — Up to 25,000 miles or one year, whichever comes first, or longer based on oil analysis.

• Severe Service(4) — Up to 15,000 miles or one year, whichever comes first, or longer based on oil analysis.


Gasoline Engine Service

• In gasoline engines, oil drain intervals may be extended up to two times (2X) the OEM* recommended drain interval (not to exceed 15,000 miles without oil analysis) or one year, whichever comes first.
Replace AMSOIL Ea™ full flow filter at the time of oil change up to 25,000 miles. Replace other brand oil filters at standard OEM* intervals.


TYPICAL TECHNICAL PROPERTIES
Synthetic 10w30/SAE 30 Diesel Oil (ACD) - Revised as of 1/06
Kinematic Viscosity @ 100°C, cSt (ASTM D-445)
10.9
Kinematic Viscosity @ 40°C, cSt (ASTM D-445)
71.4
Viscosity Index (ASTM D-2270)
141
Cold Crank Simulator Apparent Viscosity @ -25°C, cP (ASTM D-2602)
5165
Pour Point °C (°F) (ASTM D-97)
-38 (-36)
Flash Point °C (°F) (ASTM D-92)
232 (450)
Fire Point °C (°F) (ASTM D-92)
246 (475)
Noack Volatility, % weight loss (g/100g) (ASTM D-5800)
6.3
Four Ball Wear Test (ASTM D 4172B: 40 kg, 75°C, 1200 rpm, 1 hour, Scar in mm)
0.40
Total Base Number
12.0

[ July 02, 2006, 05:19 PM: Message edited by: Bio-T ]

 

[bruce381]

Yeah if you can also make a multi and a straight wt at the same cost you can sell to 2 different mindsets and only blend 1 product I guess.
bruce

 

[TooSlick]

This product used to be marketed for the old, two stroke Detroit Diesels, which called for a straight weight oil. They get the VI of 141 from the basestock blend without adding polymeric thickeners, so by definition it's also a straight weight. The original 30wt ACD product they came out with back in 1975 would have tested out to about a 15w30, but that's not a standard grade, so they never advertised that fact.

Degraded VI's tend to lead to high temp varnish deposits and piston ring sticking, so minimizing or eliminating them is a good idea if you can achieve the required low/high temp properties. This is one of the main reasons why I don't like the 0w-40/5w-50 grades....

TS

 

[msparks]

So Ted, wouldn't this be a great oil if you lived in the south? Especially if you have a slude prone engine. I migth try some of this on my next oil change instead of the HDD.

 

[bruce381]

quote:

---

Originally posted by TooSlick:
This product used to be marketed for the old, two stroke Detroit Diesels, which called for a straight weight oil. They get the VI of 141 from the basestock blend without adding polymeric thickeners, so by definition it's also a straight weight. The original 30wt ACD product they came out with back in 1975 would have tested out to about a 15w30, but that's not a standard grade, so they never advertised that fact.

Degraded VI's tend to lead to high temp varnish deposits and piston ring sticking, so minimizing or eliminating them is a good idea if you can achieve the required low/high temp properties. This is one of the main reasons why I don't like the 0w-40/5w-50 grades....

TS

---

too me that is why synthetic blends are kind of a no start deal they still have VII's so whats the point use a good dino or full PAO/ESTER syn IMHO.
bruce

 

[JHZR2]

msparks: from your post, can I assume that VIIs ARE used in the HDD oil, at least to the best of your knowledge???

Thanks!

JMH

 

[XS650]

quote:

---

Originally posted by TooSlick:
This product used to be marketed for the old, two stroke Detroit Diesels, which called for a straight weight oil. They get the VI of 141 from the basestock blend without adding polymeric thickeners, so by definition it's also a straight weight. The original 30wt ACD product they came out with back in 1975 would have tested out to about a 15w30, but that's not a standard grade, so they never advertised that fact.


TS

---

A minor point, but 15w30 is a standard grade. No one is presently licensed by API to make it, but it's a standard.

http://eolcs.api.org/DisplayViscosities.asp

 

[mechtech]

They would be tested the same.
The viscosity would be very thick at the low temp rating, however.
Single weight oils are for very specific needs.

 

[TooSlick]

Msparks,

I think it's a good alternative to the 15w40/AME for cold weather diesel use, or if you have a mixed gas/diesel fleet and want to run the same oil in everything.

I'm not sure TDI performance would be as good as the HDD,since I suspect the HT/HS viscosity of ACD is lower, ie a VI of 141 vs 174 for HDD.

TS