First time towing with Denali and have a few questions for the forum

[gfarmcafe]

The tow/trailer mode allows the transmission to stay in a lower gear longer as you accelerate and gain speed. It will shift somewhat harsher than normal, but doesn't seem to hurt anything. Also, you don't get maximum horse power for the 6.0 gasser until around 4,000 to 4,300 RPM, which sounds like it's about ready to fly. We love our 2500 HD, but realize it won't pass many gas stations, but it gets you there and in complete comfort. Enjoy it!

[CedarCreekWoody]

Just to re emphasize something mentioned early, don't use cruise control. Use it only on flat level roads. Sometimes it is best to let your speed drop a bit on hills to maintain effective RPM. A cruise control may at times fully accelerate in an attempt to maintain speed.

[mrpep]

Originally Posted by gfarmcafe

The tow/trailer mode allows the transmission to stay in a lower gear longer as you accelerate and gain speed. It will shift somewhat harsher than normal, but doesn't seem to hurt anything. Also, you don't get maximum horse power for the 6.0 gasser until around 4,000 to 4,300 RPM, which sounds like it's about ready to fly. We love our 2500 HD, but realize it won't pass many gas stations, but it gets you there and in complete comfort. Enjoy it!

What kind of gas do you get in that 2500HD when you tow?


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[rockfordroo]

mrpep: On my 2009 Silverado (5.3L) I would run my cruise control. When approaching a hill at say, 65 mph, I'd bump it up a couple mph, say 67 mph, then as I start up the hill, I'd drop it back to 65 mph. If it started slowing to about where I started (65 mph), I'd drop the cruise down a couple more mph, say 63 mph. With a little practice, and not monster hills, you CAN keep it from downshifting.

Haven't towed with my 2500 HD 6.0L yet.

[gfarmcafe]

Originally Posted by mrpep

What kind of gas do you get in that 2500HD when you tow?


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We get around 9-11 MPG towing on flat to rolling interstates of Illinois, Missouri and Kentucky, but less (7-9) when pulling in the Ozarks or Smokies when heading to Florida.
Our trailer weighs out around 6,000 pounds and we keep the speed down to around 65 with 4.10 gears.

[mrpep]

Originally Posted by gfarmcafe

We get around 9-11 MPG towing on flat to rolling interstates of Illinois, Missouri and Kentucky, but less (7-9) when pulling in the Ozarks or Smokies when heading to Florida.
Our trailer weighs out around 6,000 pounds and we keep the speed down to around 65 with 4.10 gears.

Interesting, I wonder how I got so few mph ? The 2500 has a larger engine too , doesn't it? And you have the 4.10 which is suppose to use more gas.


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[rockfordroo]

Originally Posted by mrpep

Interesting, I wonder how I got so few mph ? The 2500 has a larger engine too , doesn't it? And you have the 4.10 which is suppose to use more gas.


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Drag has as much to do with mpg as weight or anything else. Everybody's setup is just a little different, and we all drive a little different, so it's very difficult to really compare anything.

[Platokidd]

2009 chevy 2500hd 6.0 3.73 rear 6 speed tranny. I tow in 5th gear in tow-haul mode and only use cruise on flats. 7.5 to 10 mpg towing and 15 mpg other.

[gfarmcafe]

Originally Posted by rockfordroo

Drag has as much to do with mpg as weight or anything else. Everybody's setup is just a little different, and we all drive a little different, so it's very difficult to really compare anything.

Agree totally. He has to find out what's best for his style of driving and accept what he's got. We made the change from 1/2 ton to 3/4 ton at the expense of MPG, but we're happy with that knowing we can trade for something bigger later on.

[mrpep]

Ok, no I don't feel so bad - I guess towing is the main cause for gas usage


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[northstar1960]

Originally Posted by mrpep

Ok, no I don't feel so bad - I guess towing is the main cause for gas usage


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and using cruise control ! use cruise less and you can get better mpg

[mrpep]

Ok so just got back home and it was a whole different ride. This time I averaged 11.9 mpg, I had one weird rpm spike just to 4500 rpm , I rode it for about 20 seconds and then decided to tap the brakes which stops it. Since it was now my second tow with with this vehicle I felt much more comfortable and was at 70 mph, one hand - she handles really well . I even stopped at a weigh station and I'm 2000 lbs under the max gwcr so that's a good felling. This tells me I can actually upgrade my tt now [emoji4].


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[EDABEUT]

I had a 2001 1/2 ton Silverado with the 5.3 that I towed a 7000 lb TT with. I did not use the tow/haul mode in this truck as what you are feeling is the trany waiting to long to downshift and it would downshift 2 gears at once. It would not do this when not using the tow/haul mode with the 4 speed trany. The newer 6 speeds are a lot smoother on the downshifting. I always used my cruise control. To much work to not use it and keep a steady speed. No real advantage in the older trucks using the tow/haul. All it did was reprogram the shift points. Try not using it and see how you like it.

[mrpep]

Originally Posted by jughrad

You should actually try to leave it in the high RPM gear the whole time and not let her shift so much. My Denali has a manual shift capability and I leave it in a single gear on hills.



You should have a digital readout of your transmission temperature. You will notice that it stays cooler when you are running higher RPMs.



You need to keep that transmission temperature below 200 degrees. With lower RPMs you are probably not getting a full converter lock on your transmission and the clutch may slip under load.



That 6.0 L engine is designed to operate at 4000 RPM with no problem. Your transmission is not capable of operating above 200 degrees without damage.

Hm, my trans was about 215 f for the most part, it is in the 90s out here. So maybe I need an aftermarket cooler.


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[Platokidd]

Originally Posted by mrpep

Hm, my trans was about 215 f for the most part, it is in the 90s out here. So maybe I need an aftermarket cooler.


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If you dont have a tranny cooler get one. easy to install.

[mrpep]

Originally Posted by Platokidd

If you dont have a tranny cooler get one. easy to install.

My tv has one but wonder if I should a second ..


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[northstar1960]

Originally Posted by mrpep

Hm, my trans was about 215 f for the most part, it is in the 90s out here. So maybe I need an aftermarket cooler.


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i run about 160 when towing 195 when heading up the steep passes in Colorado and the west . 3 tranny coolers 2 factory and one aftermarket

[asquared]

Originally Posted by mrpep

Ok so just got back home and it was a whole different ride. This time I averaged 11.9 mpg, I had one weird rpm spike just to 4500 rpm , I rode it for about 20 seconds and then decided to tap the brakes which stops it. Since it was now my second tow with with this vehicle I felt much more comfortable and was at 70 mph, one hand - she handles really well . I even stopped at a weigh station and I'm 2000 lbs under the max gwcr so that's a good felling. This tells me I can actually upgrade my tt now [emoji4].


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Running 70 is not a good idea if you have the standard ST tires that are only rated to 65 mph.

[mrpep]

Originally Posted by asquared

Running 70 is not a good idea if you have the standard ST tires that are only rated to 65 mph.

i agree, I just didnt realize it but when I did I would slow down.

[Asrabbit]

MRPEP what did you do with your van? My wife had a 1999 Chevrolet conversion van for years and loved it. We finally sold it when we ended up with her mom's Subaru Forester. It was sort of a sad day to say goodbye to that van as so much life had gone on, (and I mean hauling kids around and stuff like that), in that van. By the time we sold it, it had many miles on it and the front end steering was a little loose, (it sort of drifted around a little), but otherwise it was in great shape.