Morning

The previous owner of my 97 XJ was running synthetic, and I'd like to switch back to dino. Anything special I need to do, or can I just swap when I change the oil next? I've heard both answers for other cars, wasn't sure for the 'Kee.

 

nothing special needed. why they change though?

 

From what I've gathered, it sounds like the 4.0s benefit from the thicker oil and more frequent changes. I know syn can help run a bit cooler, but it's just my preference I guess.

 

thicker oil comes from the weight value. at cold temps they may appear to be different but once they reach operating temps they are the same.

 

the engine benefits a lot more when it's not trying to pump molasses in cold temps. syn oil is better in every aspect.

 

I run syn oil in everything "EXCEPT" my Diesels and my XJ those get Shell Rotella and are changed very often. Why because they are used under "Severe Operating Conditions" stop and go city driving for the diesels short trips and in dirty off road conditions. All oil is cheap so the cost isn't the factor for me anyway and I use NAPA/WIX filters high mileage motors in all of them.