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Oil viscosity for Pentastar 3.6

Jeepdog8100

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The specified oil viscosity for the 3.6 is 0W20. Ever since i have owned this vehicle, the valve train has been on the noisy side.
There was a test performed on Youtube by a channel named Project Farm. In that test the 0W20 and 5W20 oil viscosities were evaluated. What the test revealed was that the 0W20 did not protect the wear surfaces. The 5W20 far out performed the 0W20 viscosity.
For the last 4 oil changes i have used the 5W20 viscosity against the factory recomendation. I noticed that the valve train noise was much less noticeable. There are a lot of warnings about using oil viscosities other than what the factory recommends. However, Jeep as well as most car manufacturers are under a great deal of pressure to increase fuel mileage or pay fines to the government. It is my opinion that we the consumer are at risk of shorter engine life for a 1/2 mpg improvement.
My 2018 JL 3.6 now has 100,050 miles and is running very well on the 5W20 viscosity synthetic oil. I have read about others that have switched to 5W30 weight for the warmer months. I think that it makes a lot of since to use a higher viscosity oil for higher mileage engines, especially in the summer months. I would be interested in hearing other comments on the above.
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kah.mun.rah

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3.6L? Isn't the 2.0L better? In all seriousness it's good to hear that you have had a better experience with 5W20. I just finished an oil change on my 3.6L and was wondering if it was time for me to graduate from 0W20. The bigger question....5 quarts or 6?
 

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The specified oil viscosity for the 3.6 is 0W20. Ever since i have owned this vehicle, the valve train has been on the noisy side.
There was a test performed on Youtube by a channel named Project Farm. In that test the 0W20 and 5W20 oil viscosities were evaluated. What the test revealed was that the 0W20 did not protect the wear surfaces. The 5W20 far out performed the 0W20 viscosity.
For the last 4 oil changes i have used the 5W20 viscosity against the factory recomendation. I noticed that the valve train noise was much less noticeable. There are a lot of warnings about using oil viscosities other than what the factory recommends. However, Jeep as well as most car manufacturers are under a great deal of pressure to increase fuel mileage or pay fines to the government. It is my opinion that we the consumer are at risk of shorter engine life for a 1/2 mpg improvement.
My 2018 JL 3.6 now has 100,050 miles and is running very well on the 5W20 viscosity synthetic oil. I have read about others that have switched to 5W30 weight for the warmer months. I think that it makes a lot of since to use a higher viscosity oil for higher mileage engines, especially in the summer months. I would be interested in hearing other comments on the above.
There are somewhere between 578 and 964 threads on this topic.

Bottom line:

- This engine is old. It came out 15 years ago. It was designed for, and originally spec'd, 5W30 oil.

- There is ONE reason and one reason only why Jeep changed the spec for the 3.6 and 5.7 engines to 0W20 and it's the almighty dollar. The EPA gives automakers kickback for specifying thinner oils and also longer change intervals....neither of which are better for engines.

- 0W20 oils don't hold a film on the cam and lifters as well overnight, so cold starts are more likely to be "dry" starts which are damaging to the valvetrain.

- Almost everyone I know who has had valvetrain issues and oil cooler leaks was using the crap 0W20 oil and/or letting the dealership service their vehicle.

- I've had 5 of these 3.6 engines in 5 different vehicles and all were flawless. Last one I had was in a 2020 Grand Cherokee and it had 202k miles when I traded it off 11 months ago.
 

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flyer92

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The argument in favor of higher oil viscosity makes total sense, but what happens if/when your engine requires a warranty repair? When that occurs, owners who change their own oil (like myself) must provide proof of oil and filter purchases, which will clearly show that a non-approved oil was used. This is an easy way for Stellantis to slither out of covering the repair even though it is under warranty, and I have actually seen this happen before with a friend's 2.0L. Although I stick with the factory-approved oil, I also send it off for analysis at every oil change. Not only does this allow me to monitor the health of the engine and quality of the used oil, but also helps to show the dealership how the engine degraded over time....using the approved oil. Frankly, my oil analysis reports have been excellent over the years and indicate that it still retains high viscosity over several thousand miles in demanding driving conditions. My last Pentastar was still going strong after 150K miles, so I haven't seen a need to depart from the factory's recommendation. As others have stated, there are no less than 578 pages of debate on this specific topic, so do your research and proceed however you like....it's your Jeep after all
 

YBABRAT

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Yet this 2019 120k on ODO Pentastar V2.0 proves you all wrong with 0w-20. And I drive it hard too! The issue is not oil... the issue is contaminants. Your V2.0 Pentastar's oiling system funtions as hydraulics for cam and rockers. There is a reason why brakes and trannys don't function well with old fluid. Contaminants and viscocity are key reasons and is the same with VVT. And yes a Pentastar V1.0 has oiling issues... but don't equate them wirh V2.0 Pentastars. A smart buyer will walk away from a band aid jeep.
 

KHR Racing

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I Finally switched over to 5w-30 a week ago. VERY HAPPY! I use Mobil 1. I’ve been wanting to do this for probably close to almost 2 years now. Wish I would’ve did this two years ago.
 

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vetygud

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I started using Valvoline Protect and Restore 5W-30 last summer, but switched back to 0W-20 during the winter months. I just have a hard time running the heavier weight oil when the temps drop consistently below -0°F or colder. I have used Mobil 1 on all of my vehicles forever but decided to give Valvoline Protect and Restore a try. So far I am happy and the valve train noise has gone away on start up. I change oil twice a year, at about every 5K miles.
 
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Trout Slayer

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Oh my goodness.
Time for four roses single batch...

Jeep Wrangler JL Oil viscosity for Pentastar 3.6 1767211111526-i
 

Valpo Jeep

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MS-6395 s the spec to follow. Many weights are covered in that spec. 0W20 is recommended but not required by Jeep. The weight is recommended as it allows slightly better fuel economy to help with the brand CAFE requirements. This means a why they installed th FAD as well. It ts worth about 0.5 MPG increase from what I remember reading.
 

WXman

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The argument in favor of higher oil viscosity makes total sense, but what happens if/when your engine requires a warranty repair? When that occurs, owners who change their own oil (like myself) must provide proof of oil and filter purchases, which will clearly show that a non-approved oil was used. This is an easy way for Stellantis to slither out of covering the repair even though it is under warranty, and I have actually seen this happen before with a friend's 2.0L. Although I stick with the factory-approved oil, I also send it off for analysis at every oil change. Not only does this allow me to monitor the health of the engine and quality of the used oil, but also helps to show the dealership how the engine degraded over time....using the approved oil. Frankly, my oil analysis reports have been excellent over the years and indicate that it still retains high viscosity over several thousand miles in demanding driving conditions. My last Pentastar was still going strong after 150K miles, so I haven't seen a need to depart from the factory's recommendation. As others have stated, there are no less than 578 pages of debate on this specific topic, so do your research and proceed however you like....it's your Jeep after all
Well the first thing that would happen is your lawyer would require them to prove that the oil you used is not approved. There's a reason why the owner's manual says that 0w20 is recommended. The key word there is recommended. Any lawyer worth his salt would immediately go to the fact that in other countries 5w30 is the oil spec for this engine and it also was the oil spec for this engine in the United States originally.
 

flyer92

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Well the first thing that would happen is your lawyer would require them to prove that the oil you used is not approved. There's a reason why the owner's manual says that 0w20 is recommended. The key word there is recommended. Any lawyer worth his salt would immediately go to the fact that in other countries 5w30 is the oil spec for this engine and it also was the oil spec for this engine in the United States originally.
True, but Stellantis stops talking as soon as you bring lawyers into the conversation. They have their own legion of high-powered legal counsel on their side as well, and schmucks like us have a very good chance of losing the case. If that occurs, the plaintiff is then liable for all court costs and attorney fees, making it an untenable strategy. Ask me how I know...
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