Towing in mountains

[TexasTwoStep]

2022 Duramax hd 3500 dually /16k 5th wheel

So I understand when descending steep grades the truck should be in drive, cruise control, tow haul with exhaust brake on. Is this correct? On older models I never used the cruise control.

[gjames50]

Reference this manual: https://www.chevrolet.com/content/da...-ebrochure.pdf

On page 12 is reads. "Cruise Grade Braking Standard on Silverado 1500 LTD, Silverado 1500, Silverado HD, Suburban and Tahoe, Cruise Grade Braking is enabled when cruise control is active. It assists in maintaining driver selected speed when driving on downhill grades by using the engine and transmission to slow the vehicle."

-and-

"Tow/Haul Mode Grade Braking Included on Silverado 1500 LTD, Silverado 1500, Silverado HD, Suburban and Tahoe, when Tow/Haul mode is enabled, it assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle."

[00 Buckshot]

You will still get the braking without cruise control by tapping the brake but you are right, I set the cruise at 5mph less than I want to go because the truck will go 5mph over the cruise setting before it kicks in.


You are wasting your time and effort if you try to down shift in the manual setting. Your RPMs will go thru the roof but you get no braking.


Happy travels.

[move on]

You can quickly go through a set of brakes when driving through the mountains with cruise on. Older vehicles did not brake in cruise control mode going down hill but newer ones do.

[carybosse]

I thought the diesel exhaust engine braking mode operated anytime the TOW/HAUL mode was activated.

Follow the manual, these newer vehicles have too much electronics to second guess them.

[Bill Nourse]

I don't use cruise going down hill. Touch the brake pedal at the speed you want descent and exhaust brake and tow/haul will hold the speed. There was a test on the Ike Gauntlet (7% 8 mile grade at 11,000 ft. 16,000 trailer) where the truck went down the grade at 50 MPH + or - with only 2 brake applications and no cruise.

I went off of the Mogollon Rim on I-17 in Az. at 55mph using this method and never touched the brakes after the initial application. This is 10 or so miles of 6 to 7% grades and I was towing a 16,000 toy hauler.

[beerdude]

Originally Posted by TexasTwoStep

2022 Duramax hd 3500 dually /16k 5th wheel

So I understand when descending steep grades the truck should be in drive, cruise control, tow haul with exhaust brake on. Is this correct? On older models I never used the cruise control.

That's how I tow with mine, granted mine is previous generation. If twisties are involved with the decent, though, then I turn off cruise and quick brake taps will commence engine braking good enough as Buckshot noted earlier.

[Nwcid]

It depends on the type of roadway you are on.

Mine is a 2016 not 2022.

If I am towing a heavy load, my exhaust brake switch is always on and I am typically in tow/haul mode.

If I am on the highway I will set my cruise at the speed I want to go. It does not matter the terrain. Uphill, downhill, etc and the truck will maintain that speed.

If I am on back roads, typically county roads, where a set seed is not appropriate, I do not use my cruise.

I have since upgraded to a bigger truck and use the 3 speed jake brake.

[Rhagfo]

Well not sure about GM, we have a Ram with likely the best EB in the industry. I use mine all the time towing or not, but when in T/H it becomes very aggressive. I set it on Full, and if cruse is on it will hold speed. If cruse is off and I lift off the throttle it will attempt to bring the rig to a near stop.

If you have adaptive cruise if the EB can’t maintain the speed it may apply the service brakes a bit to help slow.

[Rhagfo]

Originally Posted by move on

You can quickly go through a set of brakes when driving through the mountains with cruise on. Older vehicles did not brake in cruise control mode going down hill but newer ones do.

Not with a diesel with EB in operation.

[Rhagfo]

Originally Posted by gjames50

Reference this manual: https://www.chevrolet.com/content/da...-ebrochure.pdf

On page 12 is reads. "Cruise Grade Braking Standard on Silverado 1500 LTD, Silverado 1500, Silverado HD, Suburban and Tahoe, Cruise Grade Braking is enabled when cruise control is active. It assists in maintaining driver selected speed when driving on downhill grades by using the engine and transmission to slow the vehicle."

-and-

"Tow/Haul Mode Grade Braking Included on Silverado 1500 LTD, Silverado 1500, Silverado HD, Suburban and Tahoe, when Tow/Haul mode is enabled, it assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle."

The OP is driving a 3500 diesel with an exhaust brake, not a gas 1500!

[Yosemite77]

TexasTwoStep, congrats on the new truck! What you’re planning is perfect. The exhaust brake paired with cruise control makes towing in the mountains so easy. You’ll love that truck.
FWIW , I have a 2018 Duramax.

[TexasTwoStep]

Thanks for the responses.

[xc-mark]

tow haul , exhaust brake on and driving with your foot will get the best fuel economy and safer driving down hill. Its best to be proactive before you come to a hill and a few hundred feet before the hill give it just a little power so it builds boost early . If you let the cruise drive for you it waits for it for drop 2 mph, then adds the fuel by the time the boost comes on you have dropped 3~4 mph and it adds a ton of power to make up for the lost speed. at the top of a long down hill let off befor the crest and then let it slow down 1or 2 mph before the top and if needed tap the brakes lightly once and let the engine down shift to hold the load , 3500 rpm or more is safe and nothing to be concerned about going down hill.