My son just bought the 2005 Liberty with the 2.8 diesel. All in all, we're all very impressed with the engine responce and vehicle quality. The diesel is very quiet,,,,,something like a low growl.

I've been useing AMSOIL in my truck since it was new. I'm going to check with the dealer to see if AMSOIL will be acceptable regarding keeping the warranty in effect. If so, does any one know if I can use the same weight oil we use in our cummins diesels????

 

I don't know why you wouldn't be able to use the same weight. Most deisels call for the same weight of oil. A quick check in the owners manual will tell you though.

 

Just got back from class on that engine and have the latest oil info for it at work. It uses Mobil 1, but I can't remember the weight off the top of my head. Sounded like they were pretty confused on what exactly to run in it, but the same engines in Europe (which have been used for years in the mini vans and Jeep Grand Cherokees) use 15-40. Personally I was a little disappointed in the hwy mileage estimate, but maybe real world numbers will be different.

 

Was at the dealer today and they looked up the specs. Yes, they use Mobil 1. The weight is 0-40. They state that if you can't locate the 0-40, use 5-40. I never even heard of 0-40! I'll mention the 15-40 used in Europe and see what they have to say about that.

After we left the dealership, my son tells me that he was told the oil change intervals are 12,000 miles. That "definitely",,, doesn't sound right. I said regardless of what they're saying, I wouldn't let my oil changes go over 6,000 with a synthetic.

 

12K is correct, but I know no one will go that far. I still have customers that have their cummins oil changed at 3k intervals.

 

RMRC the mobil 1 0w40 is their 'european car formula' and it is designed for gas engines. I highly recommend getting the truck and suv 5w40 which is the same as Delvac 1, one of the highest quality diesel formulated synthetics out there..

Also my vw tdi had 10,000 mile oil drain intervals and almost EVERYONE follows that. It takes a little getting used to, but the oil analysis results show that the engine does fine on those intervals. If the jeep specs 12 I wouldn't think twice about doing 10-12 with a quality synthetic. 6k with synthetic is a waste, use dino oil.

 

Thanks for the replies! Always learning something new!