Amsoil Engine Tear Down Pics

Sounds like might have been an improper balance of seal swell. FWIW, M1 0W-40 stopped the valve cover leak on my M5 too.

A lack of failure really isn't a preponderance of proof though. I used a variety of different gear oils in our Expedition diff, towed heavy with it while not being kind to it, never had a failure. I don't consider that a testament to the quality of those gear oils ;)

I know the load of 10,000HP is nuts, but it's also only for 3-4 seconds. I'd think that again, the 24hr cars might be a better benchmark, due to the extended use, but OTR truck diffs are another thing to consider, given the load they are required to deal with, for long periods of time. That's why my current stock of gear oil is Delvac 1 75W-90, which was used at the heavy truck dealer my buddy worked at.
Very valid points. To unleash 10k HP in seconds and not blow up a rear diff. Imagine that instant twist of torque.
 
How long can amsoil 0w-20 signature series last when it’s constantly at 230 degrees American

Were these flat lander cars?
 
Amsoil 5w- 30 weight signature series oils are thinner than OE and extended life 5w-30

SS 5W-30 = 10.3 cSt / 6.7% Noack / ~8% ester
XL 5W-30 = 11.3 cSt / 9.4% Noack / no ester
OE 5W-30 = 11.0 cSt / 9.4% Noack / no ester

It's likely the base oil viscosity of the SS 5W-30 is as viscous or more viscous than the XL and OE 5W-30 with less VII load thanks to better quality base oils. I'd rather have an oil that starts at 10.3 and ends at 10.0 than one that starts at 11.0 and ends at 9.5.

230°F is a normal sump temp. It's typical of engine oil to operate at +20-40°F above coolant temp. Nothing concerning there. Especially a top shelf synthetic like SS, it could hum at 260°F and be fine.
 
Amsoil is using a more viscous base in the SS. The API SP SS has increased the viscosity of the base oil, reducing polymers. They're using little VII in the SS line. That's also how the achieve a very low Noack across the line. The 62 virgin oxidation reading also suggests esters as it's been speculated, they range from 10-14%.
 
Last edited:
This is not a very scientific test and I'm not one to usually put much stock into them but nevertheless it's interesting. This guy heats varioius oils to a high temperature and see what residue is left behind.

Most of the oils leave some carbon behind. This one stood out to be because you'd expect a 5w50 to leave something behind due to the polymeric thickeners being used. The actual result was extremely good.




Example of carbon left behind in the LM sample

 
230 F isn't that hot for motor oil.
Agreed, 230° f isnt hot for motor oil. It will definitely burn off most of the impurities in oil. My only contradiction to the statement posted above is if you have one that has forced induction and gasoline direct injection especially if it's with ethanol-based fuel. If it's not getting up to temperature which can take sometimes 20 miles or more of driving, fuel can break oil down and usually the lower the weight the more its evident. During the 5W-20 and 5W-30 arguments, I would rather have the ladder thin down to a 5W-20 then begin with a 5W20 and see where it goes
 
Back
Top