My Hummer H3 has 130,000+ miles. It currently has conventional 5W-30 motor oil.

Would you ...

A. Leave the same type oil in it?

B. Change to high mileage synthetic blend?

I have spoke to mechanics, the GM Dealership and everybody has given one or the other but nobody agrees with just one option.

Thanks!

 

As long as it stays full, doesn't leak or burn off, it doesn't matter what oil you use.

I have been using Mobil 1 full synthetic and will continue to do so. Since you have to buy at least one extra quart after the 5QT Jug, I will eventually make that my 1 QT Mobil 1 high mileage additive.

 

Yep. Just keeping it changed regularly is the best thing you can do. Blackstone Labs says it basically doesn't matter. I'd just keep using what you've been using, and change it regularly.

SC