I have run 10W30 and 10W40 High mileage Mobil1 since I bought my 2002 6.0L HD Silverado (98,000 miles then, 128,000 now) I will be changing my oil before a 2000 mile road trip pulling my enclosed race trailer, what weight oil should I be running????? My oil pressure is around 45 and 50 going down the road and never drops below 40 HOT in hot weather. Could I run a 5W30 now for help with gas mileage and wear on the pump or should I stick with the 10W40 and why????

Thanks for your time, Tom

 

GM recommends 5w30 for the engine.

 

Yup, says so right on the oil fill cap, question is about higher mileage motors though. Thanks anyway, Tom

 

I think you should stick with what your running right now.....

 

you have good pressure. I see no problem with the 10w30

 

Is it eating any oil between changes? If not, I'd stick with what you are doing. If it is eating some, you might substitute a quart of oil with Lucas oil stabilizer and see if it helps any.

 

Its eating some, bout a quart every 1500 miles.

 

I've been using Shell Rotella T 15w-40 since about 40k now have over 125k w/ 5.3.