Sponsored

First oil change....AMSOIL 0w20 or 5w30.

MrZappo

Well-Known Member
First Name
Tom
Joined
Aug 9, 2020
Threads
13
Messages
780
Reaction score
1,873
Location
Granger, Indiana
Vehicle(s)
Gladiator Mojave
Occupation
Computer Consultant
LOL - too much speculation. Over-thinking. Non-engine builders making it complex.

Why thicker oil with some wear? As long as the oil pressure is there it's getting oil to where it should be and if the oil had a good rating under pressure (PSI rating among other things) there's no need to switch around. Pick one and use it regardless of miles.
I run the same oil be it the very first after I've built an engine or after I've got 40K on that same engine. Viscosity and pressure don't protect. The oil film does.
I run oils that have at least a 90 psi wear rating (as tested by an engineer) or 100psi+ is even better.
Viscosity is whatever.


Here's some quotes from an engineer and occasional racer -

• Oil flow is what carries heat away from internal engine components. Those engine components are DIRECTLY oil cooled, but only INdirectly water cooled. And better flowing thinner oil will keep critical engine components cooler because it carries heat away faster than slower flowing thicker oil can. This is especially important with plain main and rod bearings, since the flow of oil through the bearings is what cools them. If you run thicker oil than needed, you will drive up engine component temps.

Here are some comparison numbers from an 830 HP road race engine on the track:

15W50 oil = 80 psi = 265* oil sump temperature

5W20 oil = 65 psi = 240* oil sump temperature

(oil returns to the pan quicker, is cooler)


• Thinner oil flows quicker at cold start-up to begin lubricating critical engine components much more quickly than thicker oil can. Most engine wear takes place during cold start-up before oil flow can reach all the components (the longer an engine has been sitting, the more of a concern this becomes), and during warm-up while the oil is still thicker and not flowing as freely as it does during normal hot operating temperature. So, quicker flowing thinner oil will help reduce start-up and warm-up engine wear, which is actually reducing wear overall.

• The more free flowing thinner oil during cold start-up and warm-up, is also much less likely to cause the oil filter bypass to open up, compared to thicker oil. Of course if the bypass opened up, that would allow unfiltered oil to be pumped through the engine. The colder the ambient temperature, and the more rpm used when the engine is cold, the more important this becomes.

• Thinner oil also flows more freely when fully warmed-up to normal operating temperatures. And oil FLOW is lubrication, but oil pressure is NOT lubrication. Oil pressure is only a measurement of resistance to flow. Running thicker oil just to up the oil pressure is the wrong thing to do, because that only reduces oil flow/lubrication. Oil pressure in and of itself, is NOT what we are after.

Wow this is a relief ... So, either I'm not crazy which is great news ... Or were both crazy which honestly would be fine ...

Either way, I'm running my 0w20 and when my engine fails due to an internal lubrication issue Ill post back on this forum ... If forums still exist that far in the future ...
Sponsored

 

Riccochet

Well-Known Member
Joined
Aug 22, 2020
Threads
3
Messages
407
Reaction score
543
Location
NC
Vehicle(s)
2012 JKR | 2020 Ram 2500 | 2021 JT Sport
The thing is, engines don't have tighter tolerances. Not in the aspect you assume. In fact, parts wear in to be relatively equal regardless of machining tolerances. The only reason to go with lighter oils is to squeeze every last fraction of a percent of fuel efficiency out of an engine design. Lighter oils, less flow and rotational resistance, higher efficiency.

We see it with every engine, from every manufacturer, throughout the years that engine is in service.

Remember, the manufacture doesn't care one bit if your engine lasts beyond the factory warranty period. In fact, it's in their best interests if it doesn't last much longer than the warranty period.

That being said. Modern oils with good additive packages do provide good protection. Heavier weight oils are only going to add to that protection.
 

TrainMan

Well-Known Member
First Name
Jared
Joined
Mar 8, 2020
Threads
29
Messages
592
Reaction score
891
Location
Pennsylvania
Vehicle(s)
2015 Chevy Silverado, 2020 Jeep Gladiator Sport S.
I would stay with 0w20 or 5w20 when possible.

Btw I just found out there's 0w16 oil now! Probably 0w8 in a few years. Someday it will be like WD40 lol.
 

Batterycap

Well-Known Member
First Name
Timothy
Joined
Mar 9, 2025
Threads
0
Messages
78
Reaction score
87
Location
Johns Creek, GA
Vehicle(s)
2024 Jeep Gladiator Mojave X
Occupation
Tax CPA
I will be reaching 5k miles on my JTR soon, which is when I was planning to do my first oil change.

I know there have been several discussions on the topic... I know I want to go with AMSOIL Signature series, but I am torn on which one...

Jeep recommends 0w20....however I live in Central Florida so climate is an issue. I have always run 30w oil in my vehicles in Florida.

Which should I go with? Any concerns over warranty if I go with something other than what factory recommends(5w30) or is 0w20 fine for hot climate?

Thanks,
Another interesting perspective:
 

Sponsored

Batterycap

Well-Known Member
First Name
Timothy
Joined
Mar 9, 2025
Threads
0
Messages
78
Reaction score
87
Location
Johns Creek, GA
Vehicle(s)
2024 Jeep Gladiator Mojave X
Occupation
Tax CPA
I would stay with 0w20 or 5w20 when possible.

Btw I just found out there's 0w16 oil now! Probably 0w8 in a few years. Someday it will be like WD40 lol.
0W-8 is already on the shelves at Wal-Mart - for Toyotas.
 

WILDHOBO

Well-Known Member
First Name
Dan
Joined
Sep 24, 2021
Threads
73
Messages
11,716
Reaction score
17,839
Location
Colorado
Vehicle(s)
2021 Gladiator Rubicon
Occupation
Network Engineer
Vehicle Showcase
1
Ill probably go with 0w20 until warranty is up then switch. I personally think the push to 0w20 has nothing to do with life and optimal protection of the engine but rather MPG and meeting government "standards".

Given my experience with my wife's Renegade....I no longer trust dealers to do even the simplest of things like oil changes....so not sure ill use the Wave changes. Not to mention....ill be ready for first oil change long before this whole virus lockdown is over ...not sure I want to deal with having to take Jeep to dealer all things considered.
Good choices in my opinion. Just use the best, non amsoil, 0w20 you can find during warranty. And I agree that free oil changes aren’t free, if the dealer sucks at doing them well. I used penzoil 0w20 until 60k miles (Powertrain warranty), then switched to valvoline. I’m now running Valvoline 0w20 high mileage, which I started after 75k miles. Zero issues with my engine.
 

gobs

Member
Joined
Apr 24, 2026
Threads
1
Messages
8
Reaction score
5
Location
FL
Vehicle(s)
2022 jeep gladiator
Occupation
IT software analyst
Speaking of making it easier.....my one issue was I have really rough pavement on driveway and scratched my arm up pretty bad getting up under the JT. Anyone recommend any low enough profile automotive creepers that would work with JTRs height? I really do not want to have to use ramps.
I have one one of these from Lowes
VersaTex 36-in x 60-in Black Rubber Outdoor Utility Mat
Sponsored

 
 







Top