I live in southern California so I just run 10w30 year around, lowest temps here was 31-32f which happened this year when it's snowed for the first time in 10 years

I run 10w30 here in Michigan all year round, no problems.

I run 10w-40 diesel oil

I love how the sell zinc oil additives now when you can just buy diesel oil that already has it lol

Well I picked up some valvoline syntec 10w-30, I run schaeffers 5w-40 9000 series in my 50trim srt-4 and its damn good oil! my uncle runs it in everything he has and has done it for years with great results. I have read and talked to alot of people that are running the synthetic diesel oil in there gas engines with great luck, that's why i was kind of curious of how many of you where doing so. How about dumping some sea foam in the crank case before i change it? good idea beings i just bought it? Thanks again fella's

is zinc important?

10W30 like the manual says.

I run whatever is cheapest between Valvoline, Mobil and Quaker State when I hit the parts store. But my rig gets its oil changed once a year whether or not it needs it! LOL As far as weight I run the 10w-30 variety.

I see no need not to trust AMC on their recommendation of oil weight. It has lasted nearly 200,000 miles on god knows how bad of maintenance and it will probably make it another thousand if its lucky.

Best Oil Around. Has High Levels Of Zinc In It!!!! Its really big on the Subaru forums. Used it in the STi, Conquest and Xterra. Its about 19 bux a gallon from Wally World!!

Amsoil 10w-40XL

If your going to buy Quaker state or Pennzoil buy Walmart super tech. It's the same. The company bottles oil for all three companies and one more. Just can't think of the name. I run super techs synthetic 10w30 in my metro. It's the same as Pennzoil ultra synthetic. Works fine. Zero problems. I change it every 5k and could go longer. But I usually don't. And here in western pa the 5 qt jug of supertech synthetic is 18 bucks. So not bad. I think Pennzoil ultra is 21 then Mobil one is 24. But that's all at Wal-Mart.

Sent from my DROID INCREDIBLE using Cherokee Forum

Blackstone lab oil reports have proven that Rotella T6 is better than Amsoil.....

Zinc helps reduce metal to metal wear. Used to be in most oils but was removed in gasoline engine oils around '06 I believe for emissions reasons. It's important in the 4.0 because we have a flat tappet cam which is a major wear area. Diesel oils still have zinc. Plus more detergents to keep it all clean.

Sent from my DROIDX using Cherokee Forum

I use switched to 15-40 diesel oil for summer time in kansas.

I know my grandpa was a firm believer in diesel oil, he ran it in all his 300 straight six ford engines and they always ran like a top. they ran smooth as glass and he never had any problems with them. I was pondering the thought of the shell rotella t6 full synthetic 5w-40. I thought there would be a few of you on here running diesel oil do to the benefits of the additives and extra protection.

It's puzzling why so many use 10WXX when 5WXX is available in their favorite brand.