Can I use high mileage oil in my TJ?

I just use the cheapest conventional oil Walmart has, and either the Mopar filter or the Fram whichever they have in stock. Change my oil every 3000 Miles.
I agree with all that except rarely is a 3k mile oil change interval needed. Jiffy Lube is who started pushing that to boost their income.
 
I agree with all that except rarely is a 3k mile oil change interval needed. Jiffy Lube is who started pushing that to boost their income.

I understand that, but I am back to daily driving mine. 80 miles round trip a day. It's just peace of mind for me really.

God I love driving my Jeep, it's like the Eagles song "Peaceful easy feeling"
 
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I just use the cheapest conventional oil Walmart has, and either the Mopar filter or the Fram whichever they have in stock. Change my oil every 3000 Miles.

Same here. (y) Our local Walmart had a closeout on Mopar oil filters, so I bought all they had for $2 each.
supertech2 (3).webp
 
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I tried using Castrol Edge high mileage full synthetic and within a week developed a nasty RMS leak. Immediately switched back to Castrol GTX and within 2 weeks the leak was gone.
Castrol full synthetic is what started the massive RMS leak in my former daily driver BMW. That's the only car since the 60's I ever ran synthetic engine oil in, and then its RMS dried up and started leaking.
 
Just my experience , not trying to start an "oil war " . I have run Mobil 1 10-30 High Mileage full synthetic in my 99 242 since 2008 and 101,000 miles ago.
And my wife's 04 242 since 2011 and 122,000 miles ago . No rear main leaks .
Maybe we have the only two TJ's that can use synthetic oil without leaking like the Exxon Valdez . :)

Nope you aren't alone. Same experience just different oil.
 
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So you like what your running

I assume that's a question and if so, yes. Super Tech oil isn't top of the line but these old Jeeps don't need top of the line oil. It is a solid oil at a very good price. I was using Mobil 1 when I first got it and it had a little rear main leak. Not bad but did have a slow seep. Switched to Super Tech 5W30 synthetic High Mileage and it dropped to almost nothing. I say almost because you can see a little oil buildup overtime back there but no drips like before.

Don't overthink it. Give the oil you have a try. If it leaks worse than it did, try something else. These old Jeeps like to mark their territory. Getting one that doesn't leak whatsoever is kind of like a unicorn or a sasquatch. They don't exist although lots of people believe they do!!
 
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Another sample of one, maybe two, here. I bought a 2003 TJ with 46,xxx miles in 2008 and used 10-30 High Mileage full synthetic Mobil 1 until I totaled it at 290,xxx miles (daily driven). Never a leak. I bought this other 2003 Tj with 17,xxx miles in 2017 and noticed small oil seeping in the RMS. Started the same 10-30 High Mileage full synthetic Mobil 1 and the seepage stopped. No oil leaks. This one is a weekend warrior, now at 32,xxx miles.
 
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Just my experience , not trying to start an "oil war " . I have run Mobil 1 10-30 High Mileage full synthetic in my 99 242 since 2008 and 101,000 miles ago.
And my wife's 04 242 since 2011 and 122,000 miles ago . No rear main leaks .
Maybe we have the only two TJ's that can use synthetic oil without leaking like the Exxon Valdez . :)

Nope, same oil here, no leaks in our 04