I heard Royal Purple will do in One test but fail the rest, ill see if I still have the article and brb.

N/M Don't have it anymore . But yeah I heard that it will pass one test, but then fail other set of tests and come in on the bottom. Don't know if thats true or not.

 

thanks for all the input...

 

CoralDoc Posted on Jan 22 2008, 02:52 PM
To add: the "correct viscosity" is the viscosity at operating temp.
That means a xxW-40 or xxW-30.
Go as low as you can afford (or want) for the xx

IMO the F20/F22 on xxW-30 weight oil is a good team.
And you know what they say about a good team

A 0W-40 will be thicker at most temps then a 5W-30 anyway, the 0W isn't magic.
It will start to show a difference below -20C or so, maybe even lower.

If the OP just wants to spend $$, go get a UOA (as mentioned) on your current oil, get the TBN too.
That UOA will tell you how shear stable your oil IS and how much capacity of dealing with combustion by-products is left after use, so you know what your safety margin is on oil change interval.

Not every change is an improvement.
I've used a 0W-40 and like my engine better on 0W-30.

 

I am pretty sure that this has been debunked. Go read over here BITOG and learn more about oil. I use and believe that M1 10w30 HM is a great oil and is what I would suggest to you to use. Go read and learn, there is a ton of information there.