Best Oil for Chysler Jeep 4.0
- Thread starter RyanM
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Dont switch oils so quickly. Why dont you see how the RP 10w30 is working for you?
You should do a UOA,that way you'll know yourself how things are wearing. Your not gonna gain anything or learn anything if you run an oil just one time around.
RP is a good oil to run we run it our I6 trailblazer and that thing tows a 1 ton trailer every week in the heat.
I run Delo 400 15w-40 in my 4.0 Jeep, the motor has 130K and does a lot of idling and low rpm driving in 4lo so I figure it was the right choice. In the winter I just switch over to Rotell T 5w-40 as those two oils can easily be found in my area. So far so good never have had any problems with either oil, motor runs like a champ.
I run Delo 400 15w-40 in my 4.0 Jeep, the motor has 130K and does a lot of idling and low rpm driving in 4lo so I figure it was the right choice. In the winter I just switch over to Rotell T 5w-40 as those two oils can easily be found in my area. So far so good never have had any problems with either oil, motor runs like a champ.
Having just purchased one of these (a 97 Cherokee), I noted that there are literally dozens on eBay every day, many with over 150,000 miles. My guess is something else will kill the unit before the engine wears out.
4.0 is a beast. I have had 2, would have another one if it was available in my newer Jeep. I used everything in those without any issues, conventional, blend and full syn's of various brands. After about 120,000 it seemed to like Valvoline Maxlife conventional the best. Any decent oil done at proper OCI will should put the 4.0 well over 200,000
One thing to consider is the 4.0 is notorious for having a weepy rear main and I saw a little drippage when using a full synthtic, as my rear main needed to be replaced. Blends and conventional were fine though.
I ran 10-40 in summer and 10-30 in winter. If your rear main is intact, I would use PP full syn. If not, then I would run a good conventional at the appropriate weight.
Side note: I have a friend with the 4.0 in two Jeeps, he did UOA's on them last year with M1, and switched to PP due to concerns about the iron wear.
One thing to consider is the 4.0 is notorious for having a weepy rear main and I saw a little drippage when using a full synthtic, as my rear main needed to be replaced. Blends and conventional were fine though.
I ran 10-40 in summer and 10-30 in winter. If your rear main is intact, I would use PP full syn. If not, then I would run a good conventional at the appropriate weight.
Side note: I have a friend with the 4.0 in two Jeeps, he did UOA's on them last year with M1, and switched to PP due to concerns about the iron wear.
i had two jeeps also. 95 wrangler and an 01 grand.. the grand was a POS electrical wise but the motors are solid as ----.. the wrangler i traded in at 170k miles.. rear mains do leak but thats not the motor is the ---- poor quality of jeep\ chrystler products.. the inline 4.0 is one of the best motors made but everything else chrystler makes is ----. i only used conventional oil, GTX, Havoline and thats it and took it to 170k miles with no problems motor wise at all.. this is my thing run 3k mile intervals with conventional and 5k miles with syns.. the chain does eat the stuff up.. maxlife has shown good #'s, as well as PP for these motors.. run either one
That engine likes 5W40 and 10W40 oils best!!! It might like a 0W40 as well but to the best of knoldge no one has tried a 0W40 in it. We have plenty of UOA with this engine with 5W30,10W30 and 5W40. THeir might also be a few 15W40 ones in the data basse as well. to the best of my memory the 5W40 UOA for this engine seemed to be dramiticly better then anything else.
hmm i can see for 4.0's with high mileage like over 150k miles they might like it better but its not necassary for lower mileage ones. i used 10w30 for the life if mine with no issues except loud ticking with M1 but i went back to gtx 10w30 and saved $.. i think 5w40 would be ok in the summer and 10w30 or 5w30 for the winter. to me it kind of depends on where you live, cold climate, warm climate and etc.
I had a 98 4.0 Cherokee I just traded back in june. I got it with ~45k on it and traded it with ~150k. The entire life of the vehicle while in my ownership(7yrs) had 0w40 M1. I had a 93 4.0 Cherokee that had 5w40 and 0w40 M1 in it for the 4 years and 75k I put on it before upgrading to the 98. Id do a UoA once a year for them, but I dont know where theyve gotten to now. Ultimately they showed the 4.0 loved the M1 0w40. Always had great reports.
Ive been running a HDEO OW40 in my Jeeps for 2 years now.My UOA is in that forum right now with great numbers.I have used Delvac 1 5W40 with smooth results ,all year long, in all my Jeeps.
I did a post a few days ago about oil for my Jeep.
I just bought an 2005 4.0 with 17,000 miles on it.
I was going to use SuperTech full syn. 10-30.
How do I know how much zinc it has?
Do you think this oil is ok to use?
I heard that a 15-40 "diesel" oil has to much detergent in it for gas engines ..........would a 15-40 be too heavy to run in the winter?
I just bought an 2005 4.0 with 17,000 miles on it.
I was going to use SuperTech full syn. 10-30.
How do I know how much zinc it has?
Do you think this oil is ok to use?
I heard that a 15-40 "diesel" oil has to much detergent in it for gas engines ..........would a 15-40 be too heavy to run in the winter?
To much detergents, nah. The diesel oils have a robust add pack hasn't hurt my 4.0 any, 15w-40 will be a bit heavy for winter. Although you can run it, but I experience far less startup clatter when using a 0w-xx or 5w-xx oil. The rotella t 5w-40 is what I use now for winters since its easy to get.
My442, One of my friends has a TR3 that has survived haveing it's crankcase emptied and then filled with kerosine. Then to add insult to injury the previous owner his uncle would start the car and run it until oil pressure hit zero. Then he would drain and refill with fresh oil and filter. It is still onthe road as a warm weather driver. Just becuase his TR-3 has survived this torture does not make it a good idea or something I would recomend. Like wise just becuase your Jeep has survived 167,000 miles on 10W30 has absolutely no bearing on what oil produces the best UOA and least amount of consuption. Maybe he should try it your way for one OCI interval and do a UOA then do it my way and see what we see. It could very well turn out that 10W30 might be the best fit for his engine or it might show that 5W40 does a better job. With out UOA it really is hard to say. I based my recomendation on UOA on this site and owner recomendations.
I think the issue now is with the new formulated oils coming out the zinc levels are greatly reduced causing greater wear on flat tappet engine.
The 15-40 diesel oils still have high levels of zinc added.
Does anyone know what the zinc ppm for the SuperTech 10-30 full synthetic is?
Are you just repeating the internet rumor or do you have some evidence?
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