fitzz47

I've been running 0-30 syn. for a few years everything seems fine.

Ed Pursell

Right out of the 2012 manual, 5W30...I got a 2012 JKU-S bought new in July 2012 ....use 5W30

kschenkel

My 2013 says 5w30 in the manual and on the oil cap.

Tooadvanced

That interesting as my 13 said 5w20 in manual and cap

bfschor

Same with my 2013....says 5w20. And I bought mine in October 2012.

Asinine

5-30 is oem spec for my 2013. I read somewhere that Jeep specs 5-30 for fuel economy reasons.

I currently run 10-30 synthetic. This was the recommendation from folks who said their 3.6 runs quieter, and admittedly it does. Living in California, it never gets cold enough to warrant 5 weight, so I'd rather err on the high side.

jkk9

I came across Caster oil GTX Magnatec recently. Supposedly relatively new and latest in engine oil technology. Designed to leave behind, specifically, a film that protects metal on metal during cold startups. Anyone ?

Heeper

Just my 2 cents worth, but my 2010 with the 3.8 engine calls for 5w-20, and that's all I've ever put in it ( usually Castrol synthetic) Jeep now has over 80,000 miles, and it uses very little oil. I took it on a 4800 mile trip this summer that included long stretches of 80 mph on the interstate, and a couple hundred miles on dirt and gravel forest service roads. It lost less than a quart of oil during the entire trip.

jkk9

Seems with everythg I am reading, there are love/hate opinions with just about every brand and weight. And then along comes Shell Helix Ultra Extra, the newest of the new in a line of end alls. Any experienced thoughts out there ?

mr72

FWIW, a synthetic 5W20 is probably equivalent in film strength to a conventional 5W30 so you get the best of both worlds... 30W film strength and 20W compliance with the manufacturer's recommendation as well as (marginally) better fuel economy.

And each oil is a little different. Considering most JKs don't spend a lot of time revving above 4K rpm the 5W20, especially a synthetic, is probably more than good enough in protective qualities and since it flows better it will be a better lubricant, particularly when cold or at initial start-up. If it weren't for warranty concerns, I'd switch to Mobil1 0W30 in the spring and 0W20 in the fall on 6-month change intervals (for me about 5K miles). Mobil1 claims the 0W20 meets all manufacturer's requirements for 5W20 equivalence but it's a really tough call, engine longevity >100K miles vs. the chances of warranty claims being denied especially considering the probability of cylinder head issues, rear engine seal leaks, or oil cooler bases cracking. I think the 0W20 is better for an engine you plan to run for >100K miles but 5W20 is probably good enough and keeps you out of hot water with the warranty.

Anyway, point of all of this is, the difference between 5W30 and 5W20 is negligible and in particular if you are running a quality synthetic oil then it almost definitely doesn't matter.