what are you guys running in your engine for oil? im just curious on which one is really the best for my 91 with 166xxx miles. also i've read on here that 10-40 would be better for my engine during the summer. is that true? thanks!

 

I have 168XXX and i have been running QuakerState High Mileage 10w-40 with slick 50(az/nm summers the -40 just means a higher temp rating) i also throw a can of engine restore in there and i use a bigger oil filter! (look for one that is the next size up with the same gasket placement) using the bigger oil filter gives more room for contaminates to be stored and not be cycled throughout your engine. when i replaced the valve cover gasket there was no sludge and everything looked like it only have a few thousand miles on it. my engine loves the oil treatment it gets!

 

My engines sludgy as hell, needs more seafoam :P do you have a part number for the bigger oil filter or something I can tell the auto store guys? Cause they only know how to type in the car in the computer and whatever comes up is what they know...

 

I use Valvoline Maxlife 5W30 or 5W40. It's a synth blend, 30/70. Been running it since about 75K. As for filters I also use a bigger filter...Wix part # 51515. Had the pan off last month and my engine is clean as a wistle. Oh, it has 135K mile.

 

I use mobile one 10w40 but couldn't tell you how it is yet. Haven't made it to my first oil change on my new engine. Runs great tho.

 

i am not sure i just went to the shelf grabbed the oil filter that is meant for the jeep 4.0l and then looked at the bigger ones and just matched up the gasket(the threading on the general filters is all the same) its like PH8? or something like that i think (fram) and what you could do is run 1 quart of tranny fluid in place of 1 quart of engine oil for about 200 hundred miles and then doing an oil change it it will help clean stuff up (i have not personally done this but it is what the steaership does when they put the 'engine cleaner' in your car and have you do a short oil change) but its all the detergents in the tranny oil that clean the crap out of stuff. this is only like 100/200 miles of use with it tho.

 

Running Rotella T6 full synthetic 5W40 with K & N filter. Change oil and filter every 5000 miles. Just passed 130K miles on 2001 Limited.

 

i use 10w-30 diesel oil because it still has some zinc in it which will help the flat tappet lifters not wear as fast

 

Rather than post what everyone "likes", here is the definitive link for all things about motor oil:
http://www.supramania.com/aehaas/

The author calls it motor oil 101, and he knows his stuff.

Read this, learn it, and you will know more about motor oil than 99% of the gearheads out there.

 

I hate it when sites have a lot of data, only to not conlude on it in the end and state findings of which oils is preferred for what, or just better overall.

I was running Valvoline 5w30 with a fram filter, now I am running Castrol GTX with a napa gold filter.

I'll have to see how the GTX works out, only have about 50mi since the change.

 

x2 on bigger oil filter, if you can find it. Stay away from Fram (except tough guard, they are so-so)
x2 on adding tranny fluid shortly before oil change
I have used Castrol GTX 10W-30 in all cars I have owned in the last 15 years. I change religiously every 3k mi, and buy my oil at WalMart ($14.50 for 5 qt)

 

I am running 10w 30 right now with a mix of bars rear main seal leak. The seal leak did not work. I plan on changing the seals soon.... just had too much else going on right now. I plan on changing the oil this weeked coming up and I am going to seafoam the engine around wednesday and try to clean it up a little. I think I plan on running 10w 40 this next time with a combination of lucas oil treatment.

 

I hate that most of these sites try to cram the Amsoil brand down our throats. OK, it's a good product, but c'mon. I won't buy their stuff because of their marketing strategy, out of spite. Dino oil with regular changes does the same trick.

 

hmm I'll try to get a bigger oil filter next time, I'm using gtx high miliage with is a synthetic blend 10-40 btw. I've never tried the tranny fluid but heard it alot, I just use seafoam.