02 Jeep 4.0, 165K miles. 50-50 hwy/s&g driving, hot in SoCal. Don't want to spend on expensive oils at this point, change every 5-7K miles. Prev. owner used Econolube places, randomly I think. So going with ST, HM 10w30, -40, conventional or syn HM 5w30? Advice?
Jeep oil and SuperTech
- Thread starter srfdude
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Use an oil that carries the specification or license listed in your owner’s manual, the winter rating is irrelevant in your location. If Super Tech oil works within that then you’re good to go.
AutoMechanic
Site Donor 2026
I wouldn’t do it just because I couldn’t sleep at night but that’s up to you. I’d use Valvoline or Castrol or Pennzoil conventional if it was me. In my opinion it’s important to use better oils as the vehicle ages.
Jeep 4.0s thrive on cheap oil. The cheaper the better.
10w-30 Supertech and a ST2 (I believe) filter and it'll easily outlast the transmission and computer.
10w-30 Supertech and a ST2 (I believe) filter and it'll easily outlast the transmission and computer.
My Loyale, my Sonoma, my Colorado, and my S70 all had a steady diet of Super Tech synthetic for hundreds of thousands of miles. All four left my possession with bodies that were rusting away from excellent running engines.
*EDIT* The Subaru got mostly conventional Super Tech
*EDIT* The Subaru got mostly conventional Super Tech
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Why are you running a high mileage oil? You said your 4.0 has 165k miles, but that by itself is not a good reason. High Mileage oils are designed to address symptoms of wear associated with high mileage engines (e.g. oil consumption, leaking gaskets seals, certain noises, etc). There are lots of engines with over 200k miles that have no problems of any kind. And we see a lot of people whose engines have no symptoms that are running High Mileage oils for no obvious reason. Just curious what is your reason.
ST is fine. A valve cover pic was recently uploaded where a guy used ST for 150k miles, or so, and it looked like it just rolled off the assembly line. Use ST if your Jeep doesn't burn it. I use PP, but that's because of GDI and it has a slightly better NOACK than ST. I've used ST non-GDI with no problems at all.
Supertech 10-30 or 40 will be just fine.
Super Tech's fine. I used to buy Super Tech 20W-50 for my worn-out 95 Cherokee Sport 4.0L. Bought it with 124k miles, gave it to my brother with 240k miles and he ran another 60k.
My 2 cents.
My 2 cents.
There ya go...ST 20W-50 goes in. That was in 2010
Does your 4.0 leak or burn oil? Super Tech synthetic is a dollar more so why use the conventional? I would probably use the Super Tech synthetic 5w30 but I think the 4.0's call for 10w30.
that’s doubtful to state the least. Dad has a older Dakota with 300k on it. Mostly ST and harvest king 10w30 whole life without issues
ST 20w-50 is discontinued.
AutoMechanic
Site Donor 2026
Really?? I’ve seen it at Walmart the last few times I was there.
Didn’t know that. Glad I had it in 2010
I don't know how many times I've went to wally with my mind made up to try ST but I've never walked out with it, not sure what it is but I just can't bring myself to try it. I know it's good oil from all the used oil analysis and testimonials but.........
AutoMechanic
Site Donor 2026
Same here. My dad put a quart of it in his truck so far it’s ok LOL.
Are you having nightmares about that quart messing up your dad’s truck?
AutoMechanic
Site Donor 2026
Yes in some ways.
Don’t. You’re a Bitoger now.
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