Arkgunner

How does it compare to Mobil 1? Can you mix the two if they are the same weight?

AraiGP4

Why bother? I would stick with the recommended weight Mobil1 unless I needed a quart of oil and couldn't find Mobil1. Then I would change back to the recommended oil at the first opportunity. GM recommends 5W-30 Mobil1 for a reason. I haven't read any complaints about it yet.

sallen619

welcome2try

Why mix? Either you get one or the other, but if I had the choice I would go with AMSOIL, once my warranty expires. I am do in 5 months, here comes AMSOIL SYNTHETIC.

Royal purple going in the tranny and rear end next week. And yes I have a friendly dealership..

Arkgunner

I was given 8 q of Valvoline- so I could make one full change and mix the rest with M1 on the next change.

lemans 07

I have been running valvoline synthetic in both my trucks ('01 tahoe/'02 sierra) for over 5 years. I have nothing bad to say about the stuff. I think any leading brand synthetic will perform about the same for everyday driving and a stock or slightly modified engine.

C66 Racing

Appreciate your consideration of AMSOIL. I just dropped you a PM with info about the AMSOIL Preferred Customer Program.

C66 Racing

I don't have a lot of test data available to compare the two, but the little I have favor's Mobil 1. Valvoline list's the NOACK Volatility (measure of the oil's likely to boil off) of their synthetic 5w30 at 13%. The last test data I have on Mobil 1 showed it at about 9%. Valvoline lists their TBN at 8. The last test data I have on Mobil 1 showed it at .8.57. Total Base Number (TBN) is the measurement of a lubricant's reserve alkalinity, which aids in the control of acids formed during the combustion process. The higher a motor oil's TBN, the more effective it is in suspending wear-causing contaminants and reducing the corrosive effects of acids over an extended period of time.

And you can mix the two.