what weight oil is everyone running with their current mileage?

I have a 2001 cherokee with 110k now. but i just changed my oil for the first time in a year since i got it.. and before you razz me about it! it only got 5k mi put on it last year and had a fresh oil change when i bought it. it only got driven on sundays and it wasnt hard driving or if i loaned it out to family or friends while their cars were down. anyways. i put 10w30 mobile 1 in it but since ive changed the oil and started daily driving it the engine seems noisier like its knocking (not loud) but it has 20-30psi hot idle and 40+ driving. living in FL should i run a heavier weight like 10w40 or straight 40w since it does run on the hotter side to begin with and the FL heat doesnt help any either.. any thoughs or opinions are greately appreciated, Thanks

 

I've got a '91 with @ 270,000 miles on it and I run 10w40 in it.

 

What does the owner manual say? My 96 calls for 10w-30, but I am gonna run 5w-30 next change.

 

10/30 Mobil 1 should be just fine. You can try a 10/40 or 15/40 down in that heat no problem if you like. Running the lightest weight your engine is quiet with would seem an OK way to choose. Within reason, lol. No 90/140 gear oil....

 

10W-30 Mobil 1 is the best. But what filter did you use?

 

You're starting to sound like me!!

It's uncanny though, how many times a Fram has caused the issues, isn't it?

F-R-A-M = Forever Ruining Automobile Motors.

 

I ran Mobil 1 5w30 with MMO in my 89. These engines are noisy. I'll say the same thing about the 4.0 as I do about the Alfa twin cam. The day you don't hear any noise, is the day you need to worry about your motor :-p. seriously though. If you have a FRAM on their. Take it off, and for the protection of our future children. Burn it.

 

As I have said before, the junkyard is full of car engines with Fram filters on them.

OCOD = Orange Can Of Death.

 

It's recommended to change your oil (depending on certain conditions) every 3,000 miles OR 3 months. Google 'bob the oil guy' and read more than you ever wanted to know about oil, especially the 10w-30 part. Most people don't know what those numbers really mean. Regular changes are much more important than weight, viscosity, brand etc.

 

few quick facts. api SN limits zinc/phos to 800ppm,

mobil1 high mileage is api SL and has roughly 25% more zinc/phos than regualr mobil1

the reason the regular mobil1 has been watered down is catalytic converter life. in order to not replace cats with the 100k warranty of new cars most the zinc/phos levels were reduced.

the two best realistic oils someone is going to be buying at walmart are either mobil1 high mileage or the T6 rotella-t from shell.

t6 would honestly be a great oil for the cherokee, it has great cold flow, 40w film and a lot of zinc in it.

either one of these is a solid choice. personally i would avoid all api SN and SM oils in these engines

 

I just changed my oil yesterday, and I run Mobil 1 High Millage 10W30 with a Bosh Distance Plus oil filter, Part #D3402.

 

Bingo. On the plus side T6 is cheaper than Mobil1 pretty much everywhere. Also, Mobil1 TDT has more zinc than the High Mileage gasoline oil if I remember the spec sheet properly. Speaking of which I hope nobody tries to run the Advanced Fuel Economy stuff in thier Jeep :O

With regards to weight, the 4.0 is specced anywhere between 0W30 and 20W50 depending on driving habits and environment. 5W40 would be great for Florida. Straight SAE40 would be a very bad idea unless your XJ lives in a garage heated to 180 degrees lol (not to mention the additives are very different). Changing often is important. The manual specifies two different service intervals at 3000 and 5000 miles, which are dependent on environment, driving habits, and engine condition. If you're interested there are companies that will perform Used Oil Analyses and give you some hard data. Some engines can run good oil up to 11,000 miles I think, others not so much.

Another big +1 to staying away from FRAM. WIX and NAPA Gold are good economical filters. Purolator and Mobil1 are high quality if you have the cash.

Also highly recommend Bob Is The Oil Guy. Find out what the "##W" means and then come back and read some of the threads here lol

 

Here's what the factory recommended in 1989:


Jeep Engine Oil Viscosity
This was taken from pages 82 and 83 of the 1989 Chrysler/Jeep owners manual.
Selecting Engine Oil Viscosity
When changing or adding engine oil select the proper grade by using the chart on the following page. Select the grade that corresponds to the ambient temperature range you expect to encounter before your next oil change.
30*F to 100*F+ 20W-40 or 20W-50
0*F to 100*F+ 10W-30 or 10W-40
-20*F to 60*F 5W-30

 

A friend of mine sent me this today. I'm not endorsing it, just throwing it out there.

 

I run oem filters on evrything. every year when my wife gets a new car i buy 4-6 factory filters