reagan

Hellow I just bought my first jeep cherokee. I am putting a new rebilt motor in it now ( I only had it a week brfore I found out how much oil it was going through ) I was wondering what brand of oil everone recommends to run it. Thanks Reagan

Kyle

I just run your average 10-30 Castrol GTX in mine. It has over 100k and is still running very strong.

jeeptech

Any name brand 5/30 or 10/30 that is on sale! 4.0's aren't particular, just need to change it and the filter regular and they stay happy a long, long time.

XJ Stryker

I have two 87 Renix i run Rotella 15/40 oil. Best oil out there for the money IMHO.

Kyle

I think this question has been asked dozens of times in every auto forum and just about everybody has a different answer. Run what makes you feel good and be done with it IMO.

wicked_xj

anything ive had to use my dads motor cycle oil from his 1100 cc lol

whowey

You are going to want to make sure you get something that meets the API-SL standards. The newer SM no longer contains the needed additives to keep the 4.0l happy.

The Zinc and Phosphorus levels are reduced in SM oils, and these are the primary anti-wear elements for flat tappet cams like the 4.0l.

BlueXJ

I broke in my engine with Castrol 10/30 then after the second oil change at 1000 miles I switched over to Mobil 1 and stayed at the same weight of oil. Have been extremely pleased with that brand but have noticed that the newer oil has less zinc and phosphorus in it which, as already stated, is not good for flat tappet engines like the 4.0L so I found some additive that will supplement the Mobil 1 with the missing ingredents, and I'm happy again.

whowey

The Mobil 1 High Mileage still carries the API-SL rating.. The other Mobil 1 varieties carry the API-SM rating.

COSXJFAN

Any name brand oil will do. Make sure it has the right additives to keep the 4.0 happy. Regular changes, especially during breakin, will be your friend!!

BlueXJ

Do the Amsoil products have zinc and phosphorus in them? Are they full synthetic as I believe them so to be? If they are then they would be a suitable alternative to Mobil 1 plus my additives.

Rainycity

I use valvoline 10/13 in everything,,

dabeast727

i use like forumla shell and prolien the stuff thats liek $1.50 and it says it complies with SL and SM regulations or watver so is that okay? This isnt my opinion, it is a question...

Kyle

Yup im sure that works just fine. IMO I would go with more of a name brand oil though.

XJ Stryker

Just stay away from penzoil.