The KN oil filters are now made in Korea and lost considerable efficiency in the process compared to the older made in the USA filters. I would choose another filter unless you have to have the welded nut. If you find them stamped made in the USA they are good old stock.
Jeep 4.0l i6 What oil should i use?
- Thread starter jbotelho15
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I feel like K&N has never been worth the money when compared to a fram ultra or even a bosch premium.
9 times out of 10 a plain jane bosch premium is good enough.
9 times out of 10 a plain jane bosch premium is good enough.
Originally Posted By: KCJeep
Defy is a top choice for the good old 4.0, good pick.
+1
Defy is a top choice for the good old 4.0, good pick.
I have run several different oils in my 4.0. Formula Shell 5w30, QS Defy 10w30, Peak 10w30 and 10w40, Delo 15w40, Mobil Super HM.
My 4.0 ran whisper quiet on Mobil Super HM. It was my favorite that I have run in it, followed by Peak 10w30. It originally ran very quiet on Defy 10w30, but it started getting noisy after about 1500 stop and go, short trip miles.
I think the 4.0's actually do really well on SN/GF-5 10w30/40 conventional oils. An inexpensive modern 10w30 conventional oil is all that is needed.
My 4.0 ran whisper quiet on Mobil Super HM. It was my favorite that I have run in it, followed by Peak 10w30. It originally ran very quiet on Defy 10w30, but it started getting noisy after about 1500 stop and go, short trip miles.
I think the 4.0's actually do really well on SN/GF-5 10w30/40 conventional oils. An inexpensive modern 10w30 conventional oil is all that is needed.
I've had my 4.0 for a little over a year and have only put about 7k on it. I've only done two oil changes so far, using Chevron Supreme and Rotella T5. Didn't notice any difference in noise/usage/drivability between the two. I should have a one year/5k UOA with the Rotella in the coming weeks.
I would think any 10w30 oil would do fine in the 4.0. My plan is to try PYB as it's an oil held in high regard here, available everywhere and inexpensive.
I would think any 10w30 oil would do fine in the 4.0. My plan is to try PYB as it's an oil held in high regard here, available everywhere and inexpensive.
rotella 10W30 and a Motorcraft FL400S filter. KC jeep will probably chime in hes pretty knowledgable on Jeeps. Just a helpful hint if you plan on doing the oil change yourself, while a 16mm wrench or sockets fits just fine, it actually takes a 5/8 wrench/socket. one of the few modern vehicles that takes an SAE plug, but a jeep is a mix of SAE/metric.
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Originally Posted By: jbotelho15
Thanks for all the tips guys! I think I'm leaning toward 5w30 and 10w30. I think I might try 10w30 next change and see how it likes it since its the factory recomendation and is already thinner than what i have now. If it still doesnt like it Ill be trying 5w30. As for brand Im still not sure but I think I am leaning towards the QS Defy still
I think you're still missing a key point: 5w30 is not "thinner" than 10w30 necessarily. There are 5w30 and 0w30 brands that are thicker than other 10w30 brands when you compare them at full operating temperature, although within a single brand its generally true than the 10w30 is at least no thinner. But brand-to-brand variation in real-world viscosity is typically bigger than 10w30 vs 5w30 same brand. Take the good old 'German Castrol' (Syntec 0w30.) Its so thick its nearly at the limit where it would have to be called a 40-grade. Definitely thicker than, say, Pennzoil Platinum 10w30.
Thanks for all the tips guys! I think I'm leaning toward 5w30 and 10w30. I think I might try 10w30 next change and see how it likes it since its the factory recomendation and is already thinner than what i have now. If it still doesnt like it Ill be trying 5w30. As for brand Im still not sure but I think I am leaning towards the QS Defy still
I think you're still missing a key point: 5w30 is not "thinner" than 10w30 necessarily. There are 5w30 and 0w30 brands that are thicker than other 10w30 brands when you compare them at full operating temperature, although within a single brand its generally true than the 10w30 is at least no thinner. But brand-to-brand variation in real-world viscosity is typically bigger than 10w30 vs 5w30 same brand. Take the good old 'German Castrol' (Syntec 0w30.) Its so thick its nearly at the limit where it would have to be called a 40-grade. Definitely thicker than, say, Pennzoil Platinum 10w30.
I have a 2003 TJ with the 4.0 with 72k miles and has always had the dreaded engine tick since 64k miles is when I got it. I've had it 4 years and I don't use it much as it's only a toy but I've changed the oil a few times and I think I tried a different brand of oil every time I changed it in fact I even tried running a quart of marvel mystery oil to help quiet it down. Well, at the end of last summer I tried the Quaker State Defy and man that just about did the trick and I'm super happy. I mean it still ticks but I'd say it reduced that cold start tick by 75%. Great oil for the 4.0!
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