Oil analysis after Towing 20K miles

[Maximus Gladius]

Your critical thinking will get you into trouble

It’s a blessing ..and a curse. Knowing when to think and when not to think…I must think about this further.

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[Glad Jeeper]

4th gear up to 65MPH on steep grade. 4500 + rpm maybe a bit higher, but always kept it under 5K rpm. I did manual shifting while towing, Used "D" when driving local. However 2nd gear holds too long. The Winnebago Hike has a high profile, so lots of wind resistance. I average 10.5 MPG for the whole trip. Some mountain driving, mpg's were as low as 8. The 3.6 is barely adequate for towing. Pure gas vs gas with 10% alcohol makes a difference on gas mileage, so when available I filled up with pure gas. I hate the 20 gal gas tank and always carried 10 gals of gas with me.

The sweet spot is 50-55 MPH

Great post. I will be towing a 20’ Grand Design with my 21 JTM. 4200-4400 loaded with a WDH. I also have a 2000 lb overland trailer that we pull. I am having the oil change this week and will probably send in a sample, then after travel season (October) I will pull another sample to compare. We found that when pulling our little trailer that it is best to drive in manual by RPM when going up steep or long grades. I am anticipating this will be the best operation when pulling the big trailer. We will see. Its first big trip is in a couple weeks to Idaho and Montana, nice climbs crossing from west washington to east washington and then from NW Idaho to montana, should be a good trip with these grades.

 

[ShadowsPapa]

I pulled 5,000 pounds in our hills. Oil samples showed up great, no added wear, no problems with towing or running a snow plow with it.
These things do great.
Unless I got into short ups and downs where there was transmission gear hunting, I let it do it's thing.
Don't know if that's one reason why I've never had a Jeep engine issue, or if it was just luck, but it worked fine. I watched transmission temperatures and tended to shift in part based on that.

 

[Gladiatorguy]

2024 JT Willys 3.6L, AT, stock tires, 0W-20. Just finished a 5,000 mile trip mostly in the Colorado rockies towing my 3,000 lb camper. Up long grades at 65-70 mph, 3rd and 4th gear, up to 5k rpm, I occasionally saw 250 oil temp. Most of the time, between 210 and 230. Oil life started with about 70% left, finished with about 2%.

 

[Maximus Gladius]

2024 JT Willys 3.6L, AT, stock tires, 0W-20. Just finished a 5,000 mile trip mostly in the Colorado rockies towing my 3,000 lb camper. Up long grades at 65-70 mph, 3rd and 4th gear, up to 5k rpm, I occasionally saw 250 oil temp. Most of the time, between 210 and 230. Oil life started with about 70% left, finished with about 2%.

Did you notice transmission temps up those grades too?

 

[Gladiatorguy]

Did you notice transmission temps up those grades too?

Yes, trans and coolant. Trans maybe 220 tops, coolant hit 235 once, but mostly 200-220. Daytime temperatures were in the high 90s several days.

 

[AstroZombie]

2022 JT Rubicon, stock tire size, 4:10 gears, 3.6 gas engine. 3 months, 20K miles, Florida to Grand Canyon then north to Grande Prairie, Alberta and back to Florida. 4 oil changes, towing a 4100 lb Winnebago Hike 100 travel trailer from April to July. Last oil change interval/mileage was almost 6K with 5% oil life indicated. This was my 'test' run for the oil analysis. I 'generally' changed the oil at 25% oil life previously. I used https://www.speediagnostix.com/ to do the testing. Everything came back 'good'. Oil life monitor was spot on according to the data and review by the engineer. I used 0W-20 initially and monitored oil temps. As the engine load (mountains) and temps rose I changed to 5W-30 and last oil change was 5W-40 (Schaeffer) 'cause it was hot. I'm back to 5W-30 (Pennzoil Platinum) since I'm not towing every day. Never had to add oil/top off during my entire trip. When I checked the oil viscosity chart based on the engine type and oil temps ... (0W or 5W) 40W oil was suggested.

Towing oil temps were as high as 240*F While towing up hill (steep grade) running about 4500 + or - rpm. 80% of the time the engine rpm's were around 3K + or - 500 rpm.

All values were good. 5.2 total metals per 1000 miles. Oil life was close to ending with 23.7 Oxidation, oil viscosity was still good @ 12.6.

No fuel dilution or water noted in the sample. I'm happy with the results and the engine is in very good operating condition after the 20K miles of 'hard use'. Used only synthetic oils, tried to use 100% pure gas, changed my air filter once before my last oil changed and added Techtron fuel treatment at each oil change.

I can share values:

ron 19 - - -
Chromium 2 - - -
Copper 2 - - -
Tin 2 - - -
Lead 1 - - -
Aluminum 3 - - -
Manganese 2 - - -
Nickel 1 - - -
Titanium 0 - - -
Total Metals: 30 - - -
Wear per 1000 Miles: 5.2 - - -

6000 miles

Towing Killed my locker position sensor.

 

[ShadowsPapa]

65 is my towing speed, regardless of the vehicle. Many reasons, among those is that it was the towing speed limit in many states for years, then the wind)air drag at higher speeds, and safety. People think only of towing weight and ignore the drag or wind sail behind them.
I notice a big difference towing a max of 65 vs. 70.

 

[DavenFla]

It’s a blessing ..and a curse. Knowing when to think and when not to think…I must think about this further.

Great post. I will be towing a 20’ Grand Design with my 21 JTM. 4200-4400 loaded with a WDH. I also have a 2000 lb overland trailer that we pull. I am having the oil change this week and will probably send in a sample, then after travel season (October) I will pull another sample to compare. We found that when pulling our little trailer that it is best to drive in manual by RPM when going up steep or long grades. I am anticipating this will be the best operation when pulling the big trailer. We will see. Its first big trip is in a couple weeks to Idaho and Montana, nice climbs crossing from west washington to east washington and then from NW Idaho to montana, should be a good trip with these grades.

Tongue weight is important to know. The travel trailer I towed had (surprisingly) 485 lb. tongue weight. I installed air bags, which made a huge difference in articulation. In addition, I had a equalizer hitch https://www.equalizerhitch.com/products/equal-i-zer-hitch/ and used REDARC elite towing controller https://www.redarcelectronics.com/us/tow-pro-elite-electric-brake-controller . Zero issues with sway or articulation. I did disconnect the equalizer bars when off road.

 

[DavenFla]

A very detailed trip, thank you for the review on the oil.

I never thought the Winnebago Hike was 4100lbs. I'm assuming that was loaded with your gear?

Yes...

 

[Gladiator007]

@ShadowsPapa says OP should have used 0W-20 SMH

 

[DavenFla]

@ShadowsPapa says OP should have used 0W-20 SMH

If you apply the science of lubrication to the (my) conditions... then 0W-20 is not the right viscosity. My conditions were high load, high heat. The number one reason for viscosity breakdown is the shear down or loss of the viscosity-index (VI) improver in the oil. This can occur due to exposure to high heat, which is the biggest factor in causing the sheer of the viscosity-index improver.

The advantages of 40W oil over 20W oil in towing applications are primarily related to viscosity and engine protection. I was running 230*-250*F at times, meaning my 40W oil with 176 VI index maintains a higher thickness and provides better lubrication under heavy loads and high heat conditions. This makes 40W oil more suitable for my towing, as it can handle the increased stress and heat generated by heavy-duty use. 40W oil at 250°F (121°C) would behave like a lower viscosity oil at normal temperatures. This is because as temperature increases, the viscosity of an oil decreases, making it thinner. In practical terms, my 5W-40 Shaeffer oil at 250°F would behave similarly viscosity as a 20W oil at normal temperatures, as the higher temperature reduces the oil's viscosity. The high VI index helps maintain viscosity from shear. 12.6 value shown on the oil sample test sheet for my 40W oil demonstrates the oil resisted shear very, very well.

In contrast, 20W oil has a lower viscosity at high temperatures, will not provide sufficient protection for engines under the strain of towing. While 20W oil flows more easily in cold temperatures, its lower viscosity at high temperatures can lead to inadequate lubrication and increased wear on engine components during towing.

Science matters. Conditions change. Lubricate based on conditions, not feelings, not what you 'think' is right, that is called... stinkin' thinkin'.

Towing high profile 4K+ trailer, 500+lbs of gear, driver plus fuel, running 3000 to 4500 RPM. Engine oil temperatures 230+ depending on grade. As I mentioned earlier, I drove in the Rocky mountains from NM, AZ, UT, WY, MT, ID, British Columbia and Alberta Canada. 20W oil is incorrect based on my conditions.

Science meets common sense.

 

[montechie]

65 is my towing speed, regardless of the vehicle. Many reasons, among those is that it was the towing speed limit in many states for years, then the wind)air drag at higher speeds, and safety. People think only of towing weight and ignore the drag or wind sail behind them.
I notice a big difference towing a max of 65 vs. 70.

I always thought of this as having "mechanical sympathy" for my tools. Just because it can go to a limit, doesn't mean I should take it up to the edge all the time. Seen plenty of nice HDs go blowing past people in our passes in the Rockies only to see the truck on the side later with the hood up.

 

[Jrgunn5150]

Have put about 3000 miles on my Mojave towing a similar weight camper.

0-20 factory recommended oil changed every 10k at the dealer.

Oil temps get up to ~240 uphill trying to maintain 65, which I can't necessarily do all the time, or won't put my Jeep through.

Jeep has 37,000 miles on it now. Will have my dog update when I die from not playing oil scientist.

 

[ShadowsPapa]

0-20 factory recommended oil changed every 10k at the dealer.

And frankly, that's how many thousands of Jeep owners do it. Forum members are usually exceptions, but the general population does just that.
Dealer oil changes, spec'd oil at spec'd weight, and tow what the Jeep can tow.
My oil analysis always came back great even after towing and snow plowing (I usually tried to get samples after non-ordinary uses like that)

Back in the mid-1970s the recommendation was 7,500 miles for "ordinary driving", I can't recall the number for towing or HD use but it was still over what many people here today do.
Superior engines, superior oils, less fuel contamination (no silly sticking choke and carburetor out of whack), and people still go by the 1960 book.

Oil temps get up to ~240 uphill trying to maintain 65, which I can't necessarily do all the time, or won't put my Jeep through.

Smart. Why do people insist they must go faster while towing?
Safter for you and your rig.

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