2001 Jeep Wrangler 4.0L

[BlueOvalFitter]

Originally Posted By: Miller88
In all honesty ... it's a 4.0. It will make 300,000 (as long as it doesn't toss a piston skirt or crack a head) regardless of what the oil is.

This is true also.

But, I will add, DON'T use 75W140! I couldn't figure out why my engine sounded like a woodpecker on a street light upon startup when I used it.

J/K about the 75W140.

 

[Thax]

Quaker State Defy 10w-30. This is a perfect oil for a 4.0L , higher than API zddp levels and a good shot of moly. It is a Syn blend , high mileage oil that will help with the 4.0L oil seeps/leaks. Many run a 40 weight in the 4.0L , however I feel it is not necessary and that the 4.0L runs best on a 30 weight. I have run this oil for 3 oci's and am very happy with the performance and low cost of this oil.

 

[KCJeep]

Originally Posted By: Thax
Quaker State Defy 10w-30. This is a perfect oil for a 4.0L , higher than API zddp levels and a good shot of moly. It is a Syn blend , high mileage oil that will help with the 4.0L oil seeps/leaks. Many run a 40 weight in the 4.0L , however I feel it is not necessary and that the 4.0L runs best on a 30 weight. I have run this oil for 3 oci's and am very happy with the performance and low cost of this oil.


I should have mentioned Defy as well. It's like the stuff was made with the 4.0 in mind, another great choice. I had absolutely no complaints with it when I ran it and I'd run it again.

 

[Thax]

Originally Posted By: KCJeep
Originally Posted By: Thax
Quaker State Defy 10w-30. This is a perfect oil for a 4.0L , higher than API zddp levels and a good shot of moly. It is a Syn blend , high mileage oil that will help with the 4.0L oil seeps/leaks. Many run a 40 weight in the 4.0L , however I feel it is not necessary and that the 4.0L runs best on a 30 weight. I have run this oil for 3 oci's and am very happy with the performance and low cost of this oil.


I should have mentioned Defy as well. It's like the stuff was made with the 4.0 in mind, another great choice. I had absolutely no complaints with it when I ran it and I'd run it again.


Yeah Ive been very happy with it , runs very smooth in my jeep. Ive been thinking as you have stated that your runs very smooth on PYB , perhaps Sopus oils loaded with Moly have something to do with this.

 

[KCJeep]

jeepman3071 and I have been doing some tandem testing for a while now, we have yet to find anything that runs smoother or quieter in the 4.0 than PYB, we also suspect it's the moly.

Many good oils for the old 4.0 though, quiet does not necessarily equate into low wear but it's nice to have it!

jeepman3071 posted a recent "over the winter" UOA of PYB 5w30. There is a good one for Defy 10w30 in the Jeep 4.0 posted on here as well.

 

[Twa717]

Thanks for all the tips.

 

[Twa717]

what is the PYB? I guess Pennzoil yellow bottle.

 

[Twa717]

Melbourne Florida

 

[BlueOvalFitter]

Originally Posted By: Twa717
what is the PYB?

Pennzoil Yellow Bottle

 

[Twa717]

Who currently makes the Mopar oil, just curious?

 

[BlueOvalFitter]

Originally Posted By: Twa717
Who currently makes the Mopar oil, just curious?

I'm not sure but PU came out with an oil for SRT vehicles.
http://www.pennzoil.com/press/new-pennzoil-ultra-0w-40-designed-for-all-srt-vehicles/

 

[Hollow]

Originally Posted By: Thax
Yeah Ive been very happy with it , runs very smooth in my jeep. Ive been thinking as you have stated that your runs very smooth on PYB , perhaps Sopus oils loaded with Moly have something to do with this.


I have found this to be true in my Subaru. It has the classic piston slap when cold, and runs smoother and quieter on Pennzoil and Quaker State conventionals, than on G-Oil synthetic.

After my FAR G-Oil is gone I think it'll be PYB, QSAD, and QSDefy until there is a formulation change.

 

[Thax]

Originally Posted By: KCJeep
jeepman3071 and I have been doing some tandem testing for a while now, we have yet to find anything that runs smoother or quieter in the 4.0 than PYB, we also suspect it's the moly.

Many good oils for the old 4.0 though, quiet does not necessarily equate into low wear but it's nice to have it!

jeepman3071 posted a recent "over the winter" UOA of PYB 5w30. There is a good one for Defy 10w30 in the Jeep 4.0 posted on here as well.
Originally Posted By: KCJeep
jeepman3071 and I have been doing some tandem testing for a while now, we have yet to find anything that runs smoother or quieter in the 4.0 than PYB, we also suspect it's the moly.

Many good oils for the old 4.0 though, quiet does not necessarily equate into low wear but it's nice to have it!

jeepman3071 posted a recent "over the winter" UOA of PYB 5w30. There is a good one for Defy 10w30 in the Jeep 4.0 posted on here as well.


If you have run both Defy and PYB , what is your opinion on these two in the 4.0L ? Is the PYB noticeably quieter ,smoother , quicker to rev etc than the Defy? I have not run PYB in the Jeep so im curious to see how it would perform compared to Defy.

 

[KCJeep]

I believe they are both great choices. The PYB is a bit thinner and it's been the quietest running oil I've tried in my 4.0 (for a Jeep 4.0 mind you). I was very happy with the Defy too and it ran really well but I also had MoS2 additive in it so it's hard to compare to straight PYB, Defy might have been louder without it.

Neither are expensive try them and see how you like them in your Jeep would be my suggestion.

 

[2James1]

Would Mobil 1 High mileage 10w-30 be good in that engine?

 

[VWright]

That is what I am currently using in my 2000 JGC 4.0, and it works great. I plan on 1 yr OCI. Mobil 1 HM, 10W30.

VW

 

[salv]

The Jeep 4.0 Loves cheap dino. Mine loved Peak 10w30. Best gas mileage and responsiveness I have had. Formula Shell bulk 5w30 was pretty good. Mobil Super HM was the quietest running. The 15w40 Delo I am running now is seems pretty good. Seems to have restored some off the line power.
It will be getting Peak 10w40 for the next 5 or 6 oil changes. I got 6 5L jugs from Autozone on closeout for $3 each. 30L for $18.