i have 131xxx miles on my 99 cherokee i want to know will it hurt anything if i switch to synthetic i always run conventional 10w 30 i want a straight answer i dont want to hear Your going to develop leaks or any of that BS just a yes or no

 

it won't hurt anything to switch to synthetic

 

If u want straight answers about motor oil, don't go to a forum, 'cause for the most part, u r just going to get opinions. Google motor oil facts.

 

Ah.. the deadly question

all the answers you will EVER need can come from here:
http://www.bobistheoilguy.com/

If you do go to synthetic though post your experiences!

 

BLUNT to be sure. Incredibly accurate though.

 

Read my Statement, then you will have your answer.

Its not going to hurt anything, that's not the question.
What are you trying to fix, by using it?

In General Synthetic is an insurance policy, and just like an insurance policy, if you buy it young, it will pay dividends later off in life.....

Your Jeep with its mileage is at (least) age 50 years old.

YMMV
Ron

 

Oh man the word OIL /U][/I]

 

Can't really speak for every vehicle let alone XJ on the planet, but I switched to full syn Mobil1 High Mileage at about 200K, and nothing drastic happened. Granted my valve cover gasket started the leak slightly, however it was the stock 20 year old gasket so I just changed it. No leak. The syn seems to do slightly better in higher and lower temps compared the the conventional I was running. Otherwise, no change.

 

Moved to chat.

 

I use full synthetic, and it is rare that I buy a vehicle with less than 150,000 miles ! No problems (oil related) !

 

I've run 10w40 con. In my jeep since I got it at 28k miles. It now has 166k. Keep using conventional or you might develop leaks.

 

The only difference between conventional and synthetic is that the synthetic is more refined to be a"smoother" molecule. This is where the leak thing comes in... The molecule can pass through a space much easier than a conventional one. It doesn't actually cause leaks. Make sense? So, if you don't have a leak, you will be fine. if you do, you may slightly notice your xj marking it's territory a little more, but hardly enough to worry about. I speak to reps at work all the time from different oil companies and they all say the same thing.

If it does leak, I would go with a higher mileage oil. It has conditioning components that will help restore seals. Not saying it will fix it, but it is supposed to help.

 

I switched at 183k and had no changes, no extra usage of the litter box (if you will.) I don't know how much switching will actually help with the life span, but it can't hurt I figure. It blackened pretty quick from starting to remove all the crap left by the Conventional though, and it idles and accelerates smoother.

 

I put 0-30 amsoil signature series in my 01 at 85k when I bought it and am currently at 134k. I changed it at 110k. And am about to change it in the next wek or so. No problems and runs like new and I average 19 mpg city highway mix

 

Must be more highway than city if ur mileage is that good