Why exactly is towing severe?

[lukejo]

I'm not doubting that towing is severe, just wondering why...
Assuming good air filtration, what does towing all summer as I do, do to oil to be considered severe?
If the cooling system is working properly, I wouldn't think heat would be that big of a factor?
Is it the extra RPMs that would mimic longer miles of non-towing OCIs?
Is there extra pressure (like PSI) being exerted on the oil?
Is shearing to a lower grade the only concern?

 

[spasm3]

I think the biggest stress is low rpm load. Lugging. You are pulling weight, more throttle angle at lower rpm until the engine gets up to speed. The load at say 2700 rpm might not be bad, but you have to pull that load from 1000rpm upwards.

 

[lukejo]

Good point. What does lugging do to oil?

 

[64bawagon]

With a proper setup I dont think it is. I have pulled trailers 10's of thousands of miles and never felt like I was hurting the truck. It does however increase the fuel consumption considerably and that can affect the maintenance needs of the engine but after a 12k oil change on my diesel with about 40% of that pulling the 10k trailer, the analysis still came back with a wide margin of use left on the oil. Bring enough vehicle to the party.

With A modern computer controlled engine with tow/haul I dont think "lugging" is an issue.

 

[Onug]

Towing requires more fuel, which generates more heat. Hotter cylinder temps, more pressure, higher spinning turbos, etc. Just because the cooling system can manage the additional heat doesn’t change the fact the cylinder and core parts of the engine are working under hotter and more harsh conditions. Cooling happens after the fuel is converted to energy. You’re also generally operating at higher RPMs, which is more work for the engine.

 

[Cujet]

In years past, I drove various gas powered vehicles towing race car trailers around the country and into Canada/Mexico. Sometimes with just one race car on an open trailer (F150 and trailer) , sometimes an enclosed trailer with 6 cars inside (E350 van + enclosed trailer) plus a large number of GM crane trucks, ladder trucks and so on towing large trailers with signs. One thing became clear, towing the heavier trailers was exceptionally hard on exhaust manifolds or headers, plus transmissions and engines had very limited lifespans.

So when people make the statement that towing is not stressful on vehicles, I think they are thinking of light duty recreational towing. And not the full throttle, heavy duty, high weight towing with pedestrian engines.

 

[Kira]

Wouldn't the compression (parts squeezing together) forces also be increased? The polymers break apart sooner and that equals wear, no?

An old sage's advice about towing, anyone? He'd say, "Don't let the tail wag the dog."

 

[krismoriah72]

Your engine must exert more force to overcome load and drag. Air and Fuel are consumed at a higher rate..

Same thing applies to non towing vehicles- that want to go fast. They must overcome drag to go faster so the more air and fuel is needed to overcome it.

Finally Walk up a flight of stairs with a 50lb backpack- Air and Fuel are consumed at a higher rate.

 

[Quattro Pete]

Originally Posted By: lukejo
Why exactly is towing severe?

Why is going uphill more severe? The engine has to work harder to accomplish it.

 

[demarpaint]

Pretty simple actually. You're burning more fuel, working the engine harder, and generating more heat. That all ads up to severe service. The engine works a lot less traveling the same distance w/o towing a trailer behind the vehicle.

 

[ls1mike]

You make some serious heat most trucks to include diesels will have exhaust manifold issues at some point. The newer ones are pretty good. All that heat under hood isn't great either.

My old 454 used to eat exhaust manifold bolts, and it cracked a few manifolds as well.

My current 02 6.0 has had a couple bolts break, but to be fair they will do it not towing, too small of a bolt head. It has been fixed in later trucks.

I camp with a couple guys who have the same truck as I and they are in excess of 150,000 miles on their units with very little work and most of those trucks lives are spent towing. Proper maintenance is key. I just rolled 50,000 on mine.

 

[CT8]

More heat, more load, more wear, more fuel being used.

 

[Snagglefoot]

I have a 2008 3/4 ton suburban with. 6-L90 transmission, separate radiator style factory transmission cooler, built in engine oil cooler, tow setting for the transmission, manual gear selector for the transmission, transmission temp gauge, and 3.73 rear end. All factory.

I tow a 6500 lb 28 ft travel trailer at 60 mph on flat highway and have taken it up grades up to 8 degrees over the continental divide.

There is a lot of wind resistance from the trailer, plus going up a hill requires a lot of energy. I have 383ft lbs of torque. My miles per gallon is cut in half. When towing up a steep hill, I slow down to 40 miles per hour. A diesel would be better but I tow less than ten times per year and don’t feel a diesel is warranted.

Firstly, the top two gears are overdrive gears. I don’t bother using them when towing as the transmission will “hunt”, constantly shifting. Shifting under load is really hard on a transmission. I tow in 4 th gear on the highway which is OK as described in the owners manual. The engine is reving at 3500 rpm at 60 mph. Of course this is tougher on the engine.

The torque is transmitted through the rear end gears, so there is a lot of loading on them.

Over all, you can fight the wear and tear with synthetic engine oil, synthetic rear gear oil, and regular engine oil changes. I change the gear oil every 50,000 miles and I now have 150,000 miles on the Burb. Hope to get to 200,000 miles.

SF

 

[Linctex]

Towing an aluminum 10,000lb RV is nothing compared to pulling a 25,000 lb bulldozer or 30,000lbs of lumber.

An engine run at near MAX Wide Open Throttle (not necessarily max RPM, tho) will ALWAYS wear out faster.

Shows up in UOA's too - as metals.

 

[BrocLuno]

The issue is heat. Not cooling system heat, but component heat. Pistons, rings, rods and big end bearing are all under higher pressure and all that sling oil coming off the crank is washing that heat away as best it can. Still getting hot.

That's why severe duty engines have things like oil cooled pistons with squirters just to manage the component heat. The oil always has to carry that heat to the cooling system before it can be shed ...

 

[DoubleWasp]

It's not rocket science.

Take a big load for your truck. Hook it to your car.

Your car will be destroyed in short order.

Towing increases stress on everything.

 

[Bryanccfshr]

Power out put is proportional to wear. Using 10-20percent of engines power is different than using 80-100% of it capability such as when towing a good load or trying to keep speed up a steep grade at high altitude.
When you push a gasoline engine like this you should follow the severe service schedule and consider an oil with a higher viscosity than the grocery getter family vehicle recomendations.

 

[BigCahuna]

So after reading all the posts it must mean excessive idling is the best possible way to operate your motor. At idle the motor is running at low speed just enough to circulate the oil. It's given just enough fuel to keep it running, so no dilution. Internal parts are hardly making contact, just barely moving. And you get the best mileage per gallon. But some will say it's also severe service.,,,

 

[Quattro Pete]

Originally Posted By: BigCahuna
And you get the best mileage per gallon.

You get the worst mileage per gallon because you are not going anywhere when idling.

 

[spasm3]

Originally Posted By: BigCahuna
So after reading all the posts it must mean excessive idling is the best possible way to operate your motor. At idle the motor is running at low speed just enough to circulate the oil. It's given just enough fuel to keep it running, so no dilution. Internal parts are hardly making contact, just barely moving. And you get the best mileage per gallon. But some will say it's also severe service.,,,


Not what my post said at all.