Run the straight 30. Your engine will love it.
1) I wouldn't run 5W30 in a 4.0L/2.5L Jeep engine in the summer(especially 115-120 deg F - wow!). It's too thin.quote:
Originally posted by oilyriser:
It'll burn 1.5% more fuel vs. 5w30, as long as you can live with that. So if you get 22 mpg, over 5000 miles that's 3.4 gallons, or about $10.
The 4.0 ..or rather the 4.2 was spec'd for 20w-50 up until the second oil crisis ..down to (I think) 32F.quote:
Originally posted by Chris142:
Ok now another one. I just went out to the garage and dug up.
2 gallons of Exxon Superflow 20w-50, 12 qts of Napa 20w-50 and 4 qts of Havoline 20w-50.
Too thick for the Jeep? I run 20w-50 in my old pickup and it does bring the oil pressure up to acceptable levels.
Save it for the truck only? What about using the 20w-50 in my air cooled quad?