Optimal Speed with 6.2 Liter Engine for Towing

[JWBGMC]

I expect to be towing a trailer in the future behind my 2016 Yukon Denali. This SUV has the 6.2 liter engine. I try to take care of the engine. For example, I am careful about making sure that oil changes are conducted at the proper time. My question is this: when I tow a trailer behind my SUV, does it matter what speed I choose? In some states, the speed limit is 65. In other states, it is 70. In Texas, the highest speed limit is 85 MPH. I want to be a safe and responsible driver. I always adhere to the speed limit. I don't care about gaining an extra 30 seconds. But my question focuses on the engine. In order to prolong the life of my 6.2 liter engine, can I drive the speed limit (85 MPH) even if I am towing 8,000 pounds? I have not found any guidance in the Owner's Manual. I try to be a "safe" driver. I also try to take care of my vehicles. Do higher speeds while towing cause more wear on the engine? Should I slow down and driver under the speed limit in order to protect my engine and drivetrain?

 

[PG01]

If you dont know that you should not tow 8000# at 85mph then you shouldn’t be towing anything.
Its not about your engine life its about ‘safety’

 

[JWBGMC]

Safety is always my priority. My question, however, is not about safety. My question is about the life of the engine. My question is the following: do higher speeds of an engine when towing causes greater wear and tear than when the engine is not towing? Are you able to understand that question?

 

[PG01]

Safety is always my priority. My question, however, is not about safety. My question is about the life of the engine. My question is the following: do higher speeds of an engine when towing causes greater wear and tear than when the engine is not towing? Are you able to understand that question?

Ill play once more but then im done, and again towing 8000# at 85mph is unsafe, even though your vehicle may be able to achieve those higher speeds with said weight.
To answer your question, which i do understand by the way, yes, higher speeds in general wear engine components faster. Towing will compound that because the engine will need to ‘work’ harder to maintain speed, on top on the engine ‘working’ harder the transmission will also need to ‘work’ harder to maintain speed thus, increasing wear.
Good luck and drive safely

 

[JTRATX]

I have the same SUV and tow about 7500LBS all loaded up. I'm in TX also and never tow above 75, and the only time I tow that fast is when it's a flat long road. Motor/trans does fine.

 

[Doubeleive]

I don't know where you are from but here on the west coast Oregon/California/Washington the maximum speed towing any trailer is 55

 

[iamdub]

"...I want to be a safe and responsible driver..." "...I try to be a "safe" driver..."

Safety is always my priority.

If safety was always your priority, then you wouldn't be the least bit concerned about going 85 MPH while towing 8,000 lbs., health of your vehicle be damned. The posted speed limit may be 85 MPH, but that likely doesn't apply to vehicles towing anything. I'm quite sure that Texas has superseding laws for such cases. They're not going to post a bunch of different speed limit signs to cover all possibilities: regular passenger vehicles, vehicles towing in excess of X lbs., vehicles of X lbs., vehicles of X number of axles, etc. Then there's the day- and nighttime speeds. That would be at least 8-10 signs for every speed limit sign location.

***EDIT*** I decided I had 12 seconds to look it up, just for my knowledge and entertainment:

http://www.statutes.legis.state.tx.us/docs/TN/htm/TN.545.htm


This sums it up:

"The maximum speed for a towing vehicle in Texas is 70 mph -- on the interstate -- unless posted otherwise. Under code 545.352, that's only in the daytime; it applies to passenger vehicles and light trucks pulling small trailers less than 26 feet long, carrying a boat, motorcycle or animals. For such small trailers, the nighttime maximum is 65 mph. For other kinds of trailers, such as fifth wheels, the maximum daytime speed is 60 mph, and that maximum drops by 5 mph at night. Common sense trumps the posted speed limit: If it's foggy, and you're still traveling at 55, the police can cite you for dangerous driving."

You being a dick on an internet forum isn't going to harm anyone, especially other nincompoops such as @Galante. You being a dick in a 7-ton, 80+ MPH missile can certainly harm or kill someone.


To address the simple question of whether or not higher engine speeds while towing causes greater wear and tear than when the engine is not towing, the simple answer is 'yes'.

 

[mtocrs1]

My rule is to keep it under 3000RPM for long durations. The 6.2 with 8 speed should be able to maintain 85mph without issues. Unless the trailer is real tall and wide causing the air brake effect.


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[mtocrs1]

Additionally I would like to add an 8k lbs trailer with properly function trailer brakes on both axles will be safer at 85mph than a much lighter load with a single axle without brakes at a lesser speed. It's all about the experience of the person towing and the equipment used.


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[Doubeleive]

ya, cant wait to see that ticket, highway patrol around here would have your nuts in a sling

 

[JWBGMC]

My rule is to keep it under 3000RPM for long durations. The 6.2 with 8 speed should be able to maintain 85mph without issues. Unless the trailer is real tall and wide causing the air brake effect.


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This response is the most useful, interesting, and relevant answer. I thank you for your insights and suggestions. You understand engines.

 

[orchidcrazy]

One thing to consider is that your Denali, even though rated to be able to tow up to a certain maximum amount, cannot tow the full amount of its rating, SAFELY for you, your vehicle engine or for folks on the road around you when you tow.

The tow rating on your Denali is for an empty towed vehicle and an empty towing vehicle - it does not include more than 1 occupant, gas, accessories you've added, hitch weight, tongue weight and the trailer weight posted as the final weight does not include anything that you typically include in a trailer when going somewhere with it. To SAFELY tow, for you, your engine, and occupants of the roads you travel on when you tow, the general rule is to keep what your towing below 80% of your capacity to allow for all those extras, but you have to maintain payload capacities, axle capacities since a proper weight distributing hitch throws weight to the front and rear, and GCVWR capacities as well.

And once within those capacities, yes, you do have to know and maintain trailering speeds wherever you travel.

There's a lot more to towing that hitching a trailer up and driving down the road. Your RPMs, air brake effect, etc. won't mean a thing when you are driving down the road way over capacity at unsafe speeds and yes, that would prematurely wear your engine.

 

[dbbd1]

It's all about the experience of the person towing and the equipment used.

Exactly!

Therefore, if the OP is asking this question...

 

[mtocrs1]

I would love for anyone telling the OP that towing 8,000lbs at 85mph will cause premature engine wear to explain. The statement is completely false. The 8k tow limit is entirely based on the Yukon chassis and rear end capacities.


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[dbbd1]

I would love for anyone telling the OP that towing 8,000lbs at 85mph will cause premature engine wear to explain. The statement is completely false. The 8k tow limit is entirely based on the Yukon chassis and rear end capacities.

It's simple logic, really...
Using anything at 100% of abilities/limits/duty cycle is going to cause parts/components to wear out faster than less than 100%.


You can drive around, everywhere you go, at 100 mph, come to a screeching stop at traffic lights and your drivetrain/brakes/tires will not last at long as they would normally.

 

[clogan2]

Operating a motor vehicle at 85 as compared to 55 will indeed cause more wear on all drive train components, regardless of whether a trailer is involved or not. Higher speed = greater wear. A trailer exacerbates it.

Simple.

Now, whether or when the resulting accelerated wear is noticeable, or measureable?

Well, like they say: "How long is a piece of string?"

 

[Big Mama]

Ok now that safety and speed limits are clear. Are you towing with it in Trailer mode? This changes the transmission gear changes. My boat weighs about 4000 pounds. Once I’m on flat land I take it out of trailer mode. I’m not sure if there’s a recommended speed or rpm for towing but the owners manual is a good place to start as it always suggests the safest method.

 

[Doubeleive]

this is why there is a term coined "extreme conditions" of course it causes wear and tear, if you don't think so then your not too bright.

 

[mtocrs1]

You guys are amazing, now the name calling and generalizations have started. I have been in the automotive/heavy equipment/industrial engine world by trade since 1996. I bet most of you have never seen an engine or drivetrain development lab.....
But hey what would I know, I only spent a 1/3 of my working career as a development engineer.
Carry on.



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[Doubeleive]

ok I can see that if the transmission and differential etcetera are doing there job properly it may not put additional strain on the motor it's self, however you can't sit there as a legitimate engineer and tell me that it doesn't put additional wear on virtually every other part of the vehicle. there is a friendly little thing out there that we call "force" I could push a piece of paper down the road at 85mph and a steel object down the road at 85mph, which one is of them is going to kill you upon impact? which one could stop faster with the same brakes? which one is going to wear out the same brakes first? which one would wear out the suspension first? this is just a tiny example of the wear and tear that happens in a "imperfect world"