Is everyone running the 5w20 thats speced for the kk?

Hi guys, first post here, but been looking around for several days...great site BTW.

I bought a 2010 KK a week ago, well actually its for my wife. Really like the vehicle and im getting ready to do the first oil change that ive done on it. Looking at it and seen its supposed to use 5w20, but that seems awful thin to me. I figured no less than 5w30, but looks like im wrong.

The jeep has 13K miles on it, and has the 6 year 100k powertrain warranty. I figure ill have to run the 5w20 oil and a mopar filter and keep records of all the maintence in case of a warranty issue down the road.

I read that the reason for the switch to 5w20 was because the goverment was on everybody about gas mileage. Said that the 5w20 gives about 1% better fuel economy, and 10% less protection than 5w30, but thats just what i read.

Whats everyones opinion on this? Is there any high mileage KK's out there that has been run on 5w20 its whole life? Or am i worried about nothing?

(yeahthat)I've been using 5w20 synthetic from day one. (2800 miles on the Od) I plan on changing it out every 5k miles.

I find Oil threads to be a bit . . . well . . :beatdeadhorse5:

BUT this is actually a really good question. Anxiously awaiting replies.

SMETNA said:

I find Oil threads to be a bit . . . well . . :beatdeadhorse5:

BUT this is actually a really good question. Anxiously awaiting replies.

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Yeah I know, I hate oil threads as much as everybody else, but this has my wheels turning.

After digging around on the internets, this:

Some body chime in if this is wrong.

What I understand is that you first number is how thin the oil can get in extreme heat. The second number is how thick it can get in extreme cold. So they both get to 5 for hot viscosity, but 5w20 stays thinner in the winter.

If you live where winter is only something that happens to other people on the news, then go with whatever is cheap. Prob 5w30

SMETNA said:

After digging around on the internets, this:

Some body chime in if this is wrong.

What I understand is that you first number is how thin the oil can get in extreme heat. The second number is how thick it can get in extreme cold. So they both get to 5 for hot viscosity, but 5w20 stays thinner in the winter.

If you live where winter is only something that happens to other people on the news, then go with whatever is cheap. Prob 5w30

Click to expand...

Got it backwards.................

The oil starts out as 5w when cold for better cold flowing,then thicken's up to 20w when hot.

Ive done some more research, and i think the 5-20 will be just fine. Im going to have to keep up with all the service records and reciepts for the powertrain warranty, and if something was to happen and they seen i hadnt run the "correct" oil in it, they would probaby kick the warranty.

My brother has been running 5w20 in his supercharged Saleen mustang since it was new, it has a little over a 100k on it now. I feel like if it will handle it, theres no reason this jeep shouldn't, after all,, thats what the oil cap says anyways.arty52:

I've been using 5-20w synthetic since I've had it, and I've changed it every 5,000 miles. No problems since I've had it. 65,000 miles here and I live in Colorado.

To add on to my previous post. It seems as though a lot of Jeep Liberty KJ owners use 5w-30. So I may switch over since both use the same engine, and If I'm not mistaken, 5w-30 is more durable in terms of weather.

I use 5w-20 since day one. I would go with what our car bible (manual) say.

Just passed 100k on my '08. 5w-20 the whole way, no problems.

Any one want to buy some Mopar 5W20?? I have (7) -5 quart containers of it sitting in the road in my garage
Be willing to make a deal!!

komatsuvarna said:

Ive done some more research, and i think the 5-20 will be just fine. Im going to have to keep up with all the service records and reciepts for the powertrain warranty, and if something was to happen and they seen i hadnt run the "correct" oil in it, they would probaby kick the warranty.

My brother has been running 5w20 in his supercharged Saleen mustang since it was new, it has a little over a 100k on it now. I feel like if it will handle it, theres no reason this jeep shouldn't, after all,, thats what the oil cap says anyways.arty52:

Click to expand...

Little difference there since the Ford engine was redesigned to use 5w-20 while the KJ's 3.7 was not and is still designed for 5w-30.