Changing recommended oil grade

Tjulo

Thread starter
Joined
May 30, 2025
Messages
3
I own a 2014 Grand cherokee V6. Recommended oil is 5w-20. As I live in the tropics where ambient temp. is between 20-40 degrees celcius all year round. Can I change the oil grade to 5w-30 or 10w-30. It seems to me that I can even use single grade 30. Can somebody comment?
 
A 10 weight oil at room temp is thicker than a 60 weight oil at operating temp. The thought that engines can ONLY operate correctly with X weight oil means that engines can only operate correctly at a certain temperature. Engines operate with relatively thick oil every time they start up. So unless you are referring to the winter rating being low enough for severely cold temps, engines operate correctly with relatively VERY thick oil every time they start up. Even if the atmospheric temp is 125F, the oil is thicker than it will be once the engine warms up to operating temp.
I would have used a grade that exists, like say a 20, 16, 12 or 8 grade to make your point, as the 10 grade, if somebody went looking for it in J300, well, of course, it isn't there. But yes, an SAE 8 would be heavier at 20C than a SAE 60 at 100C, so your point stands.
 
I own a 2014 Grand cherokee V6. Recommended oil is 5w-20. As I live in the tropics where ambient temp. is between 20-40 degrees celcius all year round. Can I change the oil grade to 5w-30 or 10w-30. It seems to me that I can even use single grade 30. Can somebody comment?

I think a lot of us got side-tracked from the original question. According to a copy of the owners manual that I found online, 5w-20 is recommended (I assume yours is the 3.6L?) but they state up to 10w-30 is fine. Here's a link to the manual I found online. Info is on pages 656-657. Hope this helps.

And by the way, for the 3.6, it even states specifically:

NOTE: MOPAR SAE 5W-30 engine oil approved to FCA

Material Standard MS-6395 such as Pennzoil, Shell Helix

or equivalent may be used when SAE 0W-20 engine oil

meeting MS-6333 is not available


https://cdn.dealereprocess.org/cdn/servicemanuals/jeep/2016-grandcherokee.pdf

Use what you want and feel comfortable about it. Just make sure it has API approval.
 
Last edited:
Before disseminating any information, please thoroughly research and comprehend the subject matter. It is crucial to avoid spreading misinformation, as it can lead to incorrect beliefs and potential harm. If you firmly believe that using a thicker viscosity is detrimental to an engine, then you are indeed misinformed.
I have moved up a grade on a few older toyotas with early vvti and they lost substantial low end torque (beyond expected windage and drag) as the higher operating viscosity retards the cam timing at a lower rpm than the design window intent, and the control valving does not interfere or correct in this range of operation. Newer vvti has tighter controls with precise cam and crank position inputs. On the other hand, older Hondas with VTEC and no cam phasers and ratcheting cam chain tensioners are largely unaffected - other than a modest windage and drag increase. - Arco
 
I think a lot of us got diverted from the original question. According to a copy of the owners manual that I found online (I did a search on Google Australia, not sure if this is an Aussie manual, but it's what came up) 5w-20 is recommended (I assume yours is the 3.2L?) but they state up to 10w-30 is fine. Here's a link to the manual I found online. It's on the page between pages 665 and 667 (yes, I'm superstitious). Hope this helps.

https://cdn.dealereprocess.org/cdn/servicemanuals/jeep/2016-cherokee.pdf
Grand Cherokee, it would have the 3.6L Pentastar engine. The manual notes that 5W-30 can be used if 5W-20 is unavailable:
1748792394796.webp


Love the fear porn about the MDS not working correctly on the HEMI if you stray from 5W-20 though, lol.
 
This reminds me of the situation I am going through. My 2020 Frontier blew the bottom end after 2000 mile since oil last changed. Was it Mobil 1 or was it the oil they put in? I called dealer and they claimed 0w20 was put in however could have been 5w30 as it was a first year for 3.8 and old body style and tech could have, although highly don't think so. Their word not mine. My opinion is a manufacturers defect nothing to do with oil, although I can spin it to be Mobil 1's fault or 5w30.
 
Grand Cherokee, it would have the 3.6L Pentastar engine. The manual notes that 5W-30 can be used if 5W-20 is unavailable:


Love the fear porn about the MDS not working correctly on the HEMI if you stray from 5W-20 though, lol.
Thank you. Updated my post. There's a lot of fear mongering in the U.S. manuals. If you look at U.S. manuals for Toyota and Subaru, they state "must use" oil X, but it's OK to use oil Y if oil X is unavailable, but must go back to oil X at next oil change. They then go on to state that if you drive "severe" driving conditions, which most of us do, then it may be better to use oil of a higher viscosity, but they give you zero guidance on what those viscosities might be.
 
If the recommended oil grade is due to CAFE and also referring to unrealistic 'normal' driving conditions, then yes. Imho, in most cases engine operation and longevity will benefit from going with a grade up. Also, change oil regularly and don't believe 10k miles OCIs if sump holds 4 to 5 quarts only.
 
I'm really curious to see if CAFE madates are going to get scaled back. EPA recently announced they are nixing the mandate on start-stop technology. CAFE standards are set by NHTSA. I'm waiting for 2026 models to hit the dealers so I can look at the owner's manuals and see what they say with regard to oil viscosity recommendations. That said though, if there is any scaling back, I don't think we'll see any potential changes in oil viscosity recommendations until MY 2027, if at all.
 
This reminds me of the situation I am going through. My 2020 Frontier blew the bottom end after 2000 mile since oil last changed. Was it Mobil 1 or was it the oil they put in? I called dealer and they claimed 0w20 was put in however could have been 5w30 as it was a first year for 3.8 and old body style and tech could have, although highly don't think so. Their word not mine. My opinion is a manufacturers defect nothing to do with oil, although I can spin it to be Mobil 1's fault or 5w30.
Probably the defective Chinese Nissan filters back then - or maybe those were still Made in Japan at y2k
 
I have been running m10w40 in my Toyota trucks and 4 runners since 2017. Current truck is a 2018 and has 93k miles on it and runs strong with no noises.

In the arctic in 30 below weather at work we ran 5w40 synthetic Chevron Delo in our gm 6.6 liter engines, no issues.
 
I own a 2014 Grand cherokee V6. Recommended oil is 5w-20. As I live in the tropics where ambient temp. is between 20-40 degrees celcius all year round. Can I change the oil grade to 5w-30 or 10w-30. It seems to me that I can even use single grade 30. Can somebody comment?
My friend's GC with the turbo diesel upped the factory viscosity recommendation when the engines were failing. It's hard some issues but is still running...
 
It's a Jeep so honestly youre just about better off not bothering to change the oil. Not like the engine will last either way hahahaha.

Sorry had to jab at modern Jeeps. Yeah going thicker won't hurt.
 
I sent a text message to my old buddy who lost his V-10. He called me today and we talked for two hours. We haven't spoken in over 10 years. I told him about this debate and I encouraged him to join BITOG to tell his story. I hope he joins. I would love to see your responses to his real-world experience.
It's not really a "debate", you used an anecdote to broad brush an entire subject with "don't stray from what the OEM" recommends, presumably because you don't understand the subject well enough to understand why that statement is being challenged.

Instead of engaging and asking questions as to WHY that has taken place, you seem to want to just double down on not understanding 🤷‍♂️
 
Last edited by a moderator:
I sent a text message to my old buddy who lost his V-10. He called me today and we talked for two hours. We haven't spoken in over 10 years. I told him about this debate and I encouraged him to join BITOG to tell his story. I hope he joins. I would love to see your responses to his real-world experience.
The biggest problem with nearly every “real world” experience is that people form conclusions based on a highly biased experience. It sounds cool to say “buddy I got real-world experience here” but often it’s inaccurate.
 
Back
Top Bottom