a1 vs a3 - how important is it really?

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Staff member
Dec 14, 2002
New Jersey
I was thinking... a lot of performance cars prefer mobil 1... mitsu lancer turbo (19 psi I believe!), porsche turbos, subaru wrx turbos, MB AMG supercharged cars... as well as a bunch of na performance cars.

and they typically use M1 10w-30, an A1 oil. Now, I think its safe to assume that under high temp/high shear, high stress conditions, and A1 oil will not hold up as well. yet, they reccomend A1 mobil1. Why is this????

-any damage that would occur wouldnt be realized until the car is way out of warranty
-the engineers at these companies are idiots or didnt think of it
-it doesnt really matter, tolerances could accept a 20wt oil just fine, so long as its synthetic

Any ideas? I just have had such a strong feeling of necessity for A3 oils (like in my brother's 3000 GT twin turbo), but maybe its not all that necessary...

Any comments?

In reading and searching the archives, Ive noted that there has apparently been discussion of how high HT/HS such as in an A3 oil is not necessarily the best thing. However, I didnt see why. The only info I pulled was that the higher the HT/HS, the lower the fuel econony compared to other equal weight oils with lower HT/HS ratings.

But what about vaporization or protection, of a synthetic, in a low-revving american engine?


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