Best 5W40 motor oil for 99 Jeep 4 liter engine?

[Carlostrece]

For Jeep 4 liter engines 5W40 synthetic is very popular with many. Another popular choice is 5W30 conventional (especially Penzoil). Personally I prefer 5W40, but which one would be best, or does it even matter which?

Shell Rotella T6 5W40 is the most popular 5W40 choice for Jeep 4 liter engines based on what I've read at various Jeep forums.

I've read some use Chevron Delo 5W40 or Supreme 5W40.

I've also read some use Mobil One 5W40.

I don't know anyone who uses Lucas 5W40, but I assume it's good.

I'm currently using Penzoil Platinum Euro 5W40 in my Jeep 4 liter engine.

Those are the only brands of 5W40 that I have access to locally. So I have to choose from those.

Which of those would be best for my Jeep 4 liter engine? Does it matter which of those I use? My gut feeling/assumption is that all brands of 5W40 are probably good, and likely better than I really need (eexcept Castrol and Royal Purple, which I don't trust for reasons I won't go into here).

 

[Carlostrece]

The other issue is price. While price doesn't have to be my deciding factor, there's no point in wasting money if there's a lower cost option that is as good for my engine.

5W40

Mobil One, Rotella, Delo, Supreme, and Penzoil Euro normal prices are $10 quart in my local area.

Mobil One, Rotella, and Delo often go on sale for $4.50 quart. That a deal!

Chev Supreme and Penzoil Euro occasionally go on sale for $7 quart.

Lucas 5W40 costs $9.33 quart. I haven't seen it on sale.

===

Based on price, Rotella T6 and Delo 5W40 are the clear winners. However, are they as good performers for my Jeep 4 liter gas engine as Penzoil Platinum Euro 5W40?

 

[Carlostrece]

P.S. - Is there a Chevron Delvac 5W40? If there is, should that be an oil I consider using? Delvac is probably available at my local Chevron truck stop. Though I have no idea what the price might be.

 

[Carlostrece]

I just learned that I also have local access to Valvoline Synpower 5w40 for around $9.50 quart, and Valvoline Premium Blue Extreme Synthetic Diesel 5w40 for $7 quart.

I don't know much about these oils. I assume they're good for my 99 Jeep 4 liter gas engine.

 

[SwampSurvivor]

These engines really don't care what's in them. I have a bunch of 0w-40 and 5w-40 along with 5w-50 - some of it may find its way to the Jeep but they don't care.

It would live just as long on a 5w-40 as a 5w-30 or 10w-30. Remember, the cam is 18 years old now. The lobes were broken in looooooong ago.

My 4.0 lives a hard life and seems to do just fine on cheap 10w-30. They don't care. I had mine bouncing off the rev limiter long enough to melt a cat and get a little warm. Even right after it had good oil pressure idling hot.

 

[69GTX]

I'd consider the 0w-40 A3/B4 specced oils as well as they really aren't all that different from the 5w-40's. And you can almost always find the 0w-40's at good prices (ie M1 current at $13/5 qt jug via Walmart after factory rebate). Pennzoil carrying a $2/qt rebate on the PP/PU's.

You just missed the December AutoZone clearances where synthetic PP/M1/Edge/Synpower 0/5w-40's often go on sale for $2/qt. Plan on stocking up this December.

 

[zeng]

Originally Posted By: Carlostrece

5W40

Mobil One, Rotella, and Delo often go on sale for $4.50 quart.

Chev Supreme and Penzoil Euro occasionally go on sale for $7 quart.

===

Based on price, Rotella T6 and Delo 5W40 are the clear winners. However, are they as good performers for my Jeep 4 liter gas engine as Penzoil Platinum Euro 5W40?


As you said, T6 and Delo are winners. I wouldn't consider Pennzoil in this context.

 

[Kruse]

Originally Posted By: Miller88
These engines really don't care what's in them.

^This, at least after the engine is broke in. I've got three 4.0 engines, with more than 750K miles using nothing more than oil that was $2/quart or less.

 

[Donald]

T6 is fine. But at slightly worse mileage than 10w30.

 

[toneydoc]

I had Castrol 0w40 in mine for a while. Mine is 23 years old now and I do not think the oil brand or weight between 30 or 40 weight makes any difference. It drips them all. I lose about 1 quart per oil change onto the asphalt or driveway. The engine is still running good. Something other than the engine will kill this Jeep when that happens.

Just put in decent oil and remember to change it from time to time

 

[BrocLuno]

What's on sale at Wal-Mart, Fred Meyer, etc. - in the xW-40 range will do just fine. If off-roading in low range you will heat soak the engine and the 40 will help. If just using as grocery getter, any xW-30 or 40 will do

 

[Carlostrece]

Originally Posted By: zeng
Originally Posted By: Carlostrece

5W40

Mobil One, Rotella, and Delo often go on sale for $4.50 quart.

Chev Supreme and Penzoil Euro occasionally go on sale for $7 quart.

===

Based on price, Rotella T6 and Delo 5W40 are the clear winners. However, are they as good performers for my Jeep 4 liter gas engine as Penzoil Platinum Euro 5W40?


As you said, T6 and Delo are winners. I wouldn't consider Pennzoil in this context.


I said T6 & Delo are winners based on price. i.e. - usually lower cost.

Why would you not consider Pennzoil? Please elaborate.

 

[Carlostrece]

Originally Posted By: Kruse
These engines really don't care what's in them. I've got three 4.0 engines, with more than 750K miles using nothing more than oil that was $2/quart or less.


More than 750K for each Jeep or combined mileage of 3 Jeeps?

 

[Carlostrece]

Originally Posted By: Donald
T6 is fine. But slightly worse mileage than 10w30.


Is that an assumption or have you tested and compared gas mileage? My experience is 5W40 synthetic gives me at least as good gas mileage as 5W30 or 10W30 conventional.
I have run highway gas mileage tests and compared.

 

[Carlostrece]

BTW - My 99 Jeep has only 40,000 miles on it. If that matters. It has no oil leaks and the rings are good.

 

[dlundblad]

The 4.0 should like any diesel or Euro 40 weight synthetic. I ran Mobil 1 Turbo Diesel Truck for the longest time until going to PYB 10w30 and 10w40.

I am currently running Castrol Edge HM 10w40, which is an A3/B4 like a Euro oil. I'd wait to find it on sale at parts stores. Sometimes Oreilly's has it for $22 with a WIX filter after rebate.

 

[Kuato]

Rotella's a good choice. I always used Amsoil 5w30 in mine with very good results up to 12000 mile intervals. UOA said it could have gone farther.

 

[bullwinkle]

Mine is still liking the NextGen MaxLife 10W40, ZERO consumption, none of it cost more than $1/quart when O'Reilly was closing it out. Three 5K OCIs per XG8A Fram Ultra.

 

[Kruse]

Originally Posted By: Carlostrece
Originally Posted By: Kruse
These engines really don't care what's in them. I've got three 4.0 engines, with more than 750K miles using nothing more than oil that was $2/quart or less.


More than 750K for each Jeep or combined mileage of 3 Jeeps?


Combined mileage of 3 Jeeps. Two '96 Cherokees and a '98 Grand Cherokee.

 

[dnewton3]

Originally Posted By: Carlostrece
For Jeep 4 liter engines 5W40 synthetic is very popular with many. Another popular choice is 5W30 conventional (especially Penzoil). Personally I prefer 5W40, but which one would be best, or does it even matter which?

Shell Rotella T6 5W40 is the most popular 5W40 choice for Jeep 4 liter engines based on what I've read at various Jeep forums.

I've read some use Chevron Delo 5W40 or Supreme 5W40.

I've also read some use Mobil One 5W40.

I don't know anyone who uses Lucas 5W40, but I assume it's good.

I'm currently using Penzoil Platinum Euro 5W40 in my Jeep 4 liter engine.

Those are the only brands of 5W40 that I have access to locally. So I have to choose from those.

Which of those would be best for my Jeep 4 liter engine? Does it matter which of those I use? My gut feeling/assumption is that all brands of 5W40 are probably good, and likely better than I really need (eexcept Castrol and Royal Purple, which I don't trust for reasons I won't go into here).



First,

to the site!

Next ... realize that while there may be a "best" lube for your particular engine, you're not going to get a concensus here on the site. In fact, you should not trust anyone here who tells you that brand X or grade Y is "best", because we don't really know what "best" means to you.

You need to define what "best" means to you. Lowest wear rates? Lowest cost? Longest OCIs?

If you REALLY want to know what's "best" in terms of these things, you're going to have to do a lot of testing. And I means a LOT of testing; perhaps a few hundred thoustand miles. That's what it takes to prove with real statistical analysis just what results will show these things. You cannot judge something in a micro sense unless you understand the variation present in the application. So you first have to run a study basis, then apply analysis, then chose another, and start all over again. In fact, there is a great likelihood that over the years it will take to do this, the formuation would change and your data would be moot.

Sorry to burst your bubble, and those of a lot of bench-lube-racers here, but that is the reality of "best".

OTOH, there are many good quality lubes that will suffice for the application. Pick one, and worry about something else in life. These "what's the best oil" threads have no merit because no one here has ever collected enough data to really prove it one way or another.

Read this:
https://bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/