quote:
Originally posted by 1 FMF:
I am using Mobil-1 0w-40 synthetic in my 2002 SS. I have only a few hundred miles on it so far (about a month) and everything runs fine. I get about the same gas mileage too, or if it's different it's not enough where I can tell.
The reason I went with 0w-40 was because my motor starts tapping about 30 seconds after startup, and is sometimes there at idle and sometimes not. Guessing it might be noisy lifters and valvetrain I hoped the 0w-40 would make the noise go away. It did not. I plan on running this oil for 7000-10k miles or till June, I do mostly easy highway driving so I figure it's good for that long, and I hope to do an analysis on it when the time comes. I will go back to a 30wt oil, probably Mobil-1 synthetic.
With the LS1 motor (Camaro's Firebirds and Corvettes), I have the GM service manual for my car and it states that for the LS1 5w-30 weight is recommended, however 10w-30 and 10w-40 weights are acceptable given the climate and availability of oils. The only warning that is written is "Do not use 20w-50 oils". Again, ?w-40 weight oils are okay according to the service manual, and I think you can also conclude that from info in the owner's manual too.