Amsoil Signature Series 0W40 vs. Euro 5W40

[stosh1]

Originally Posted By: Guitarman200806
I'm all for trying the Amsoil (use it in everything I own). But why 40wt in an S54? I thought the spec from bmw m was Castrol 10w60. I've heard of some saying the spec is too heavy and trying a 50 or 40 wt. Have you had success before using 40wt in that engine?


Originally, BMW spec'd a 5W30 wt. oil IIRC, but later changed to the 10W60 after people started experiencing some bearing failures. One of the most common theories is that the rod bearing (and possibly main bearings as well) clearance was originally spec'd too tight...and BMW's quick (i.e. cheap) Band-Aid was to change the wt. of the oil. (FWIW, I actually experienced a rod bearing failure at around 85k mi. using the Castrol 10W60) Granted the Castrol 10W60 is a relatively free flowing 60 wt. oil, but some current thinkers (myself included) feel that a thinner high quality fully synthetic 30/40 wt. oil is all that is required. According to research, a thinner (not thicker) oil, actually flows better between bearings (assuming an adequate oil supply of course).

 

[stosh1]

Originally Posted By: kschachn
Originally Posted By: stosh1
AAACK, first of all, sorry for the bad grammar & typos above. Uuumm, I guess mostly from the std. "pressure" type wear testing that I've seen. One ex. would be from the previous page: https://540ratblog.wordpress.com/ His results seem to mirror most testing that I've either seen on the interwebz or heard about. Do you have any links or evidence to support or reject it?


Oh boy. There are numerous threads on this board about that website, all of which explain in excruciating detail how it is worthless - both in methodology and data collection.


Please don't tell me you joined and posted just to resurrect this "test"?



Lol, nope, didn't join just to "resurrect" that test. I am new to the forum, so forgive the noob encroachment. Would you mind explaining why the test was invalid? Do you know of any different comparison tests?

 

[kschachn]

Originally Posted By: stosh1
Lol, nope, didn't join just to "resurrect" that test. I am new to the forum, so forgive the noob encroachment. Would you mind explaining why the test was invalid? Do you know of any different comparison tests?


Here, look through these former threads:

Other Threads

The main problems are that the test is not representative of an actual engine, and that his methodology does not lend itself to results that have the precision he thinks it has. In other words, it doesn't test anything that happens in an engine and he's measuring results (and drawing conclusions) to a much greater precision than is warranted.

 

[stosh1]

Originally Posted By: kschachn
Originally Posted By: stosh1
Lol, nope, didn't join just to "resurrect" that test. I am new to the forum, so forgive the noob encroachment. Would you mind explaining why the test was invalid? Do you know of any different comparison tests?


Here, look through these former threads:

Other Threads

The main problems are that the test is not representative of an actual engine, and that his methodology does not lend itself to results that have the precision he thinks it has. In other words, it doesn't test anything that happens in an engine and he's measuring results (and drawing conclusions) to a much greater precision than is warranted.



Thanx so much, I'll take a look!