Jeep Wrangler TJ 4.0 Oil

[BrocLuno]

Originally Posted By: 440Magnum
The 4.0 isn't terribly demanding on oil. Once broken-in, the flat tappet cam will be perfectly fine on today's SN oils with ~800 PPM of ZDDP.

That said, the 4.0 is prone to low-ish oil pressure as it racks up miles, and tends to do extremely well on 40-weight oil instead of the manual-recommended xw30. Rotella T6 5w40 is an *extremely* popular choice in the 4.0, and being a 40-weight it is allowed ~1000 PPM of ZDDP for those who want the extra peace of mind.

Unless that thing is burning a quart of oil every 500 miles, modern Xw40 levels of ZDDP will not hurt the catalyst. It was *designed* when all the available oils had more ZDDP than most today have.


+1

I'd switch to T6 in heart beat with that many miles

 

[hemitruck]

cast iron block and cast iron heads, i would use 5 40 rotella.

 

[dlundblad]

Originally Posted By: fins
Have owned a 2005 Wrangler since 2007.

For the first 8 years I used Rotella 15-40.

About 2 years ago I switched to QS Defy 10-30.....have been happy with the switch.


Sadly they've changed the QS Defy formulation. While it used to be API SL, it is now "energy conserving."

 

[lawrencerd]

In my Cherokee I prefer xw-30, 10w-40 did feel a tad sluggish.

 

[fins]

Originally Posted By: dlundblad
Originally Posted By: fins
Have owned a 2005 Wrangler since 2007.

For the first 8 years I used Rotella 15-40.

About 2 years ago I switched to QS Defy 10-30.....have been happy with the switch.


Sadly they've changed the QS Defy formulation. While it used to be API SL, it is now "energy conserving."



What is the difference in the oil now ??

 

[Nickdfresh]

Originally Posted By: fins
Originally Posted By: dlundblad
Originally Posted By: fins
Have owned a 2005 Wrangler since 2007.

For the first 8 years I used Rotella 15-40.

About 2 years ago I switched to QS Defy 10-30.....have been happy with the switch.


Sadly they've changed the QS Defy formulation. While it used to be API SL, it is now "energy conserving."



What is the difference in the oil now ??


Being SN it will have less zinc which makes zero difference in 99% of vehicles on the road. Especially since even the older SL formulation already had a lot of moly.....

 

[Garak]

Originally Posted By: fins
What is the difference in the oil now ??

In addition to what Nickdfresh stated, it may also have slightly reduced HTHS, assuming that the HTHS was elevated above a normal ILSAC 30 in the first place.

 

[BrocLuno]

As long as you are not rock crawling in 110* weather a 30 or a 40 will do fine. If I lived where it gets cold, I'd shy away from 40 for winter and daily driving. OTOH, if I was going to AZ to try some rim-rock country, I'd have a 40 in there for sure.

Use the oil that matches the situation ...

 

[TiredTrucker]

Not sure that 5w40 is so "girlie". Here is part of the sample results from a recent UOA on Schaeffer 5w40 HDEO I have been using.......

 

[Doublehaul]

I had a Rubicon with a 4.0 that went over the quarter million mile mark on a steady diet of Mobil 1 5w30. I felt then...as now...why run a 10w when 5w is available. I'd run 0w if I could get it the oil I want

 

[CT Rob]

Jeep dealer i worked at for years always put 10-40 in the 4.0 jeeps.

 

[KCJeep]

I prefer a thick for grade 30 or a light for grade 40 for the Jeep 4.0. I agree once broken in the need for high ZDDP oils seems to be a non-issue though it wouldn't hurt either. If not burning oil I'd not be the slightest concerned about cats.

I did not like 15w40 in mine when I tried it, but then again I drive the already heavy WJ which tends to test the drive ability limits of the 4.0. It works but the Jeep often feels bogged down if I don't keep the rpm's up. The 15w40 just made it worse.

 

[RatBikeRandy]

Thanks all. Changing this weekend with regular Pennzoil 10w30 and a Wix filter (the larger one). Also gonna grease it.

Will probably have a mechanic change all of the other fluids since I don't know the whole history. The air filter was really clean. Jeep has been garaged it's whole life and I definitely want to keep it tip-top. From what I understand they are pretty reliable if you keep it maintained.

What is the difference in all of the High Mileage oils out there, I've never used one?

 

[riklyn]

a little late to this thread but wanted to share my latest 4.0 experience. As background I worked for and retired from Chrysler so owned quite a few Jeeps with 4.0 including a 2000 GC with close to 300,000 on it the last time I saw it drive off.

My current Wrangler (2004 TJ) wasn't so lucky with. Bought it used in 2011, 40,000 miles. Don't know history behind it, but appeared to be very good condition. Lost lobe on cam @ 50,000. Have 60,000 on it now and using Rotella.

 

[DoubleWasp]

I've abused my Jeep in every way you can imagine. 260+k on an engine that has no detectable blowby, noise, or leak. Almost all on premium 10/30 oil.