Hi everyone - I am new to the forum, so if this post was answered previously, I apologize.
I have a 2011 GMC Yukon Denali Hybrid and I am towing a 21.5 foot Mastercraft weighing in just shy of 5100lbs. When towing it into the mountains, I notice that if i go over 60 mph, and have the rpm's over 3000 for an extended time frame, my temperature starts to go up.
When I am towing, I try and keep it under 3k rpms and am in manual 3rd or 4th gear. I found that if I leave it in drive, the engine revs harder.
My question is, has anyone else noticed this issue? The last thing I want to do is to overheat my engine.
I am not worried about the speed - if I have to stay at 60 instead of 70, I am good with that. I am more concerned about the temperature going up and working the engine too hard.
Am I just stuck with this, and if I need to do more towing, I need to get out of a hybrid and go to a diesel?
Any insight from other Yukon or Tahoe owners, would be appreciated. Thanks

 

Hi and Welcome.

Lot of users tow here.

have you check your trans temp when engine temp raises?

I haven't tow in the Tahoe, but have done some towing with the Silverado. (5900= lbs)

had seen my trans go to 195 mark, but the engine heat never changed. In a couple times I went full throttle for quite some time to pass a few convoys. No problem there !

Hope other users chime in !

 

The only thing I've ever towed is a boatload of emotional luggage ... but it didn't seem to affect the Hoe.

Perhaps a trip to the dealer or a quick call to GM customer service would be the best way to know if this is normal or of there's an issue. Tbh an engine this size shouldn't overheat if you're towing below spec loads.

 

I agree - it shouldn't - but it is pretty close of max. towing capacity. Wonder if GM fudged just a little on the numbers?

 

Thanks to all for the info. I will be calling the dealer soon - no real hurry, as boating season is basically done.

 

HyHoe - great lookin' ride! I love those wheels - those are what really sold me on my Denali Hybrid

 

Thanks.

 

I just towed my travel trailer 280 miles lasted weekend. It weighs approx 5500-6000 lbs. I tried using cruise control but any grades resulted in high rpms. Just manually throttled and occasially used cruise on flat terrain. Left trans in D. Average rpm was 2200-2300. Got about 9.6mpg with slight tail wind(5mph?). Very cool taking off from stops with just battery with that much weight. 22mpg (70mph avg)on highway w/o trailer. Overall 18mpg with 7% of that towing. 2011 Denali Hybrid.

 

General towing note: The 2 Mode does have four (4) fixed gears. However the Manual shift selection does NOT guarntee a fixed gear. Since there is no torque converter gearing down going up grades towing does little to reduce stress on the system. Manual selections down grades is the real benefit of the 2 Mode hybrid

Going up the hybrid will shift into a mode and thereby allow he engine speed to vary. This is the differentiator of the 2 Mode from all others. The Mode will maximize engine power available at any vehicle speed and keep the engine above torque peak and on the power curve. It is a little hard to get used to but no more lugging and downshifting, only to rev way up and up-shift, and repeat, and repeat...

How hard you push the accel pedal will determine how high the engine will rev up!

The horsepower peak is over 5000. I don't run them that hard becuse fuel economy towing up grade can drop to 6. I'm too cheap.

Remember that your gross combined is still 12,000 lbs. So 5100 lbs boat plus trailer plus people and gear can exceede the 12k. When I tow my 22 foot Sea Ray (3500 lb) plus trailer, kids, gear, dog, etc, I have scaled in at 12,601.

If you do get the engine or transmission too hot... 225 F engine 220F trans, the Driver Information Center DIC will actually tell you. Then it will first shut off air conditioning. If you are concerned about 3000 rpm and higher I suggest full synthetic oil to ease any worries.

 

I tow an 18' steel trailer with either an M3 or an 89 Mustang race car, tire rack, tires, tool box.... and have no issues. The water temp stays happy, the tranny temps stay normal (unless you are bad and try to tow up a very steep incline). I have the tranny fluid changed yearly (synthetic) and change the transfer case oil every other year. I've found that the most fuel efficient speed is 70mpg. At that speed I get 15 mpg. At 75 mph that will drop a mile per gallon or two.