Little backstory I think may help with opinions on my jeep: I bought my 1994 Cherokee Country (H.O.) this last October with about 234k on it, and the previous owner didn't take care of it AT ALL. All the fluids possible were brown and FULL of gunk and crud. Ran super hot, coolant was brown and thick and I had to flush the rad about three times for clear water to start running through, and changed the T-stat. Anyway, since then I've been having the oil changed every 3000 (Less, actually) and been running a "High Mileage" petroleum, non-synthetic oil that they offer at jiffy lube. Been hearing a lot of arguments about running synthetics, and I'm just wondering, would switching to synthetic (I've been eying Amsoil products) be a good idea on my now 239.3k H.O. motor?? Would it have any bad impacts?

Thanks for reading, and helping if ya post at all!

 

I've always been told with the rear main seal designed as it is, synthetics will be more likely to leak.

 

Anyone else to confirm/refute this?

 

Ive heard the same thing but ive never ran synthetics in any of the vehicles ive owned

 

X2 on never having run synthetics. I just get a good high milage oil with a GOOD filter

 

Synthetic is just a waste of money. If it has been ran on dino oil its whole life, keep using it. Switching to synthetic now could cause leaks and lifters, etc. Might start ticking.

 

Yeah, I run the most expensive high mileage oil the place has to offer (I know price doesn't guarantee quality, but it does work really really well) and was just wondering about synthetics a bit. Thanks guys!!

 

And my H.O. I6 sounds like a ticking sewing machine anyway. Haha..

 

wow... amazing the level of stupidity and rumors that goes around here sometimes.

Run whatever kind of oil you want, its not going to make a difference.
Synthetic does NOT cause leaks, they use the same additives as dino oil, but are just more stable and flow better in cold/hot.
Synthetics (good ones) do not shear like a dino oil. Yes, it still happens, but not nearly as bad.

I run whatever I feel like when its oil change time. NAPA full synthetic was on sale last time, so I bought a case. Next time Itll pry be a semi, then maybe another full or maybe even a dyno after that. Just depends.

 

^^ Listen to this kat.

Asking about oil on this forum is like asking if Coke is better than Pepsi (or vise versa).

Run whatever you can afford. Change all the fluids if they are dirty and you should be good to go.

 

Thanks Def, I hold your opinion in high regard. Given me help and correct answers on a lot of issues in previous months.

 

What do you have against dirty oil?

 

Please, We all know Coke is better, thought this argument had been settled

 

Thanks

 

Pepsi....HaHa