Towing with cruise control on?

[MillerTime]

For got to add manual says not to use in traffic situations- no brainer but since I was quoting the manual, there it is.

[B47]

Originally Posted by Road-King

In my 07 Dodge, if I press the tow/haul button once, it goes into tow/haul mode. Press it a second time and it locks out the O/D. Third press and it's back to normal.

That is different than my 2012 Ram 6.7L diesel - you press the T/H button and it is engaged and when you press it again it is disengaged. It also disengages each time the engine is turned off.

[Helmsey]

2004 Chevy Duramax\Allison - One push of the tow\haul turns it on\off, press and hold tow\haul and it locks out OD (5th gear for my truck). When on the interstate I will usually turn on CC, if I see a larger hill coming up I will hit the gas pedal until I hear the turbo spooling and can easily hold speed. I have tried locking out OD for climbing longer\steeper grades but doesn't seem to be any different than getting the turbo spooled in OD.

[J_KHawthorne]

I use CC and also Tow/Haul mode when towing on the open road and the InterStates, but kick it off in towns. I also go out of CC and switch to manual when going up hills with steeper, extended grades. I also like to switch to manual on steeper extended downgrades so the engine helps control braking.

[pappcam]

Originally Posted by J_KHawthorne

I use CC and also Tow/Haul mode when towing on the open road and the InterStates, but kick it off in towns. I also go out of CC and switch to manual when going up hills with steeper, extended grades. I also like to switch to manual on steeper extended downgrades so the engine helps control braking.

I do the same except for the kicking it into manual part. My 2011 F150 has a 6-speed and tow/haul mode that does all that for me including engine braking.

[jar3316]

Talked to my company mechanic and he was a trans shop owner for years before he "semi retired" and works for us 2 days a week doing mait. and repairs on all our vehicles.

He stated and I am quoting as close as I can. If your tach is higher at a specific gear and speed than normal (unloaded), AND the vehicle "hunts" for a lower gear more, you should always put the vehicle in the lower gear.

As for CC he said the problem is that most vehicles will not down shift until the throttle is all the way to the floor, and most CC systems will not "floor a throttle" so even a small uphill section with a strain on the truck will cause a "bogging" state in the engine and the trans will react with "hunting" and "torque slip" in the trans until the CC gives up (because it can not maintain its speed) and shuts it self down.

So in his opinion CC used for either overdrive or a lower gear while on the open HWY with the person actively monitoring the throttle, tach, and shift count will be fine and in CA I would almost say it's a must considering the 55mph speed limit when towing (I got a speeding ticket for towing an empty HF trailer at 58 once on the 99 near Sacramento cost me $400+).

I personally use CC and overdrive/Drive in my tow rig but I have a V10 and only tow a >5500lbs trailer (I turn off overdrive for hills and mountain roads up and down)

[crasher]

Guess you are finding there is no simple answer. You just have to listen/monitor your vehicle and use some common sense. Steep hills, turn it off. Heavy traffic, turn it off. Transmission hunting gears, turn it off.

Flat, free flowing interstate? Enjoy!

[BeagleIL]

Originally Posted by jar3316

the trans will react with "hunting" and "torque slip" in the trans until the CC gives up (because it can not maintain its speed) and shuts it self down.

That's a new one on me. I've used the CC while towing for years and never had it shut itself down. I think my first reaction would be to think that the whole engine bit the dust before looking to see if the CC was still on...

[wayne anthony]

My 06 Chev 2500 w/gas and 4 speed auto loses about 1mpg using cc. On almost every rise in the road it down shifts 2 gears to get up to speed right away. With the cc off, I can give it enough throttle to down shift only one gear.

[Timex]

Nothing wrong with the transmission downshifting to get up a hill is it?

[jar3316]

Originally Posted by BeagleIL

That's a new one on me. I've used the CC while towing for years and never had it shut itself down. I think my first reaction would be to think that the whole engine bit the dust before looking to see if the CC was still on...

Had it happen to me once in my old f150. wasn't paying attention and all of the sudden the whole truck just slowed and lost all power going up a hill. I had my mind somewhere else and did not notice the hill and my loss of about (i have to guess because i wasn't watching remember) 15 to 20 mph in speed. I was sure the engine died and it took me a few seconds to realize what was happening.

[schrederman]

Most CCs will disengage when the speed drops by 5mph or so due to load. You'd have to look at your owner's manual to see if it's mentioned. There is no reason not to use CC when towing out on the open road. When in tow/haul mode, the tranny and computer work together to make the best of situations. As said before, in town or hilly country, keep it off just for your own safety. My '11 F-150 with the new 5.0 does a fine job with the CC on.