PUP beat Driven

[Jeep Junkie]

I always tell people if you’re not comfortable it’s best to get everything done at the dealer. For the rest of us we run what we feel is best for our situation. My oil temps reach 250f off road so I choose a high quality 30 grade. If I was a normal driver with oil temps mostly below 220f I’d be fine with 0W-20. Most of my Jeep club run 0W-40 because they beat the snot out of their engines in mud pits….

Okay, what about this. Suppose there are two Jeeps, going from Seattle to Denver and back. One is empty, and the other one is hauling a lot and is also pulling a 4,000 lb trailer. Will the two UOA's look very different from each other?

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[jellis4148]

Does it really matter? Honestly you can change your oil every 500 miles, put the best made in it and it could blow up at 40,000 miles. Just drive the freaking thing and stop with all the posts after every time you watch a video or read something. I run 0W-20 PUP in my Jeep since the first oil change. I change it every 3,000 miles. It sounds fine and runs fine. You cause more problems to your Jeep with all the bs you do. I seriously think you need a therapist and to be put on meds.

 

[GW’s JL]

Okay, what about this. Suppose there are two Jeeps, going from Seattle to Denver and back. One is empty, and the other one is hauling a lot and is also pulling a 4,000 lb trailer. Will the two UOA's look very different from each other?

To properly use a UOA for this situation you would need to do many of these trips and do many UOA’s to establish a trend for severe service vs non severe. I believe with enough data you could establish a difference.

But IMO it’s much easier to rely on official wear studies comparing different viscosities in a controlled study. The work and cost has already been covered. Again if you’re this nervous just follow the owners manual recommendation. When I was a tech I would provide my opinion but never make the customer feel uncomfortable doing something they were unsure about.

 

[Jeep Junkie]

To properly use a UOA for this situation you would need to do many of these trips and do many UOA’s to establish a trend for severe service vs non severe. I believe with enough data you could establish a difference.

But IMO it’s much easier to rely on official wear studies comparing different viscosities in a controlled study. The work and cost has already been covered. Again if you’re this nervous just follow the owners manual recommendation. When I was a tech I would provide my opinion but never make the customer feel uncomfortable doing something they were unsure about.

I'm not nervous about shit, I'm just trying to learn

 

[Jeep Junkie]

What the hell is the use of a UOA then if a minimally stressed engine sheds as much iron as an engine pulling 5,000 lb cross country on mountain passes? That just means that a properly working oil pump and cooling system will not let an engine wear out faster even if it is super stressed. The more you stress it, the more oil pump and cooling system will get involved to keep the wear rate at the average for that engine. That's why we have oil pressure, coolant and fans.
I think UOA is a waste of money and it is only good for detecting coolant leaks and bad air filtration.

 

[GW’s JL]

What the hell is the use of a UOA then if a minimally stressed engine sheds as much iron as an engine pulling 5,000 lb cross country on mountain passes? That just means that a properly working oil pump and cooling system will not let an engine wear out faster even if it is super stressed. The more you stress it, the more oil pump and cooling system will get involved to keep the wear rate at the average for that engine. That's why we have oil pressure, coolant and fans.
I think UOA is a waste of money and it is only good for detecting coolant leaks and bad air filtration.

The actual intent of a UOA is to monitor changes in engine conditions and to determine the proper length of time an oil can last. This is why it’s mostly used by fleets. It was never intended to rank oils.

With the right data you would find severe service does impact the engine wear. Wear studies show higher viscosity has less wear. Whether you need it is the real question. Owners manuals pre cafe had specific severe service schedules and viscosity chart recommendations.

 

[Jeep Junkie]

It was never intended to rank oils.

Or to tell wear. I wonder what it will take to see 150 ppm of iron in 5000 miles in a Pentastar? That's more than 6 times the average and oil filter should have bigger particles of iron visible to the naked eye. That's some kind of catastrophic engine damage

 

[johneracer]

Okay, what about this. Suppose there are two Jeeps, going from Seattle to Denver and back. One is empty, and the other one is hauling a lot and is also pulling a 4,000 lb trailer. Will the two UOA's look very different from each other?

I think one trip will not show any difference on the UOA. Most engine wear happens on startup so better comparison would be a car that is driven often short distances so lots of startups and one car going far, towing but very infrequent start up. I bet you UOA would show a noticeable difference. And to make things even come confusing, this may not matter at all, both engines may last and cover similar milage but fail due to something else entirely. The point is, oil is only one ingredient in engine longevity and the regular oil changes with decent oil are all that is needed. Going over and above with 500-mile oil changes, boutique oils, UOA and worry about oil, may not be important in the overall engine longevity. There are many other variables. How clean the environment is? dust? Hot climate, cold climate? Lots of short driving where engine doesnt fully warm up? Humidity?

 

[GW’s JL]

Lake developed this chart when he worked at Driven. How to choose viscosity based on oil temperature and bearing clearance. It’s served me well over the years. The W rating would be dependent on your winter time lows but the grade still applies.

 

[Jeep Junkie]

Lake developed this chart when he worked at Driven. How to choose viscosity based on oil temperature and bearing clearance. It’s served me well over the years. The W rating would be dependent on your winter time lows but the grade still applies.

So ESP 0W-30 in the Pentastar agrees with that chart? And Seattle area for the temperature, 25° to 95°

 

[GW’s JL]

So ESP 0W-30 in the Pentastar agrees with that chart? And Seattle area for the temperature, 25° to 95°

That’s exactly what I use. PUP 5W-30 would work for you as well.

 

[Jeep Junkie]

That’s exactly what I use.

I'm going to give it a try, and if I don't find big iron chunks in my oil filter, then I will stick to it

 

[Jeep Junkie]

My dad uses 20W60 diesel oil in his third gen gas 4runner, I also want to feel a little tough

 

[johneracer]

In Socal I usually run 5W-30 in winter (Winter lol) and in summer switch to 10W-30 or even 10W-40 if its a particularly hot summer. I also mainly use the jeep for off-roading so lots of slow speed, hot overall temps. Not much air going over radiator and oil cooler. Due to how my jeep is used I do 3000 mile oil changes. Oil is cheap. Plus it gives me opportunity to look it over.

 

[Jeep Junkie]

That’s exactly what I use. PUP 5W-30 would work for you as well.

Real quick, when viscosity modifiers get chopped up, can the detergents hold them, or they end up becoming varnish? I'm asking this because I read somewhere that Toyota oil uses a stupid amount of viscosity modifiers, and the engines end up with a lot of varnish.

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