Originally Posted By: ARMY_Guy
Sorry to let yous guys down... but I'm 2nd guessing my choice, with that Mobil 1 0w30 (Advanced Fuel Economy) at Walmart for $16 after my $10 Mobil 1 rebate... GM Boy's right, why go Dino after using synth; especially when freezing weather's headed in. Man I need some here fella's. Please. Why cant I find that dang receipt!! ;-(
-A
You could poo in the valve cover and your 4.0L would run fine. Dino, syn, it doesn't matter much with a 2.5L/258/4.0L engine. Some of the best used oil analysis I've seen are on dino. I wouldn't run a 20 weight if your Jeep sees any decent trail time, but in a daily driver it would probably be fine in winter. In spring/summer/fall, I use SAE30, 10W40, or 15W40. It's all good.