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Discussion Starter #1
I recommend NOT using the tow/haul feature if you want to maximize your gas mileage and maintain your speed when going up hills. I have used the tow/haul and allowed the transmission to shift up and down on it's own, but I get much better mileage using the LOW (L) gear setting.

When towing, I put the transmission in L and hit the plus paddle four times to allow the transmission to shift, on it's own, up to fifth gear. When I approach a hill, I hit the minus paddle to downshift into fourth gear just prior to hitting the grade. This allows me to maintain my speed up the grade by increasing the RPM. If the speed goes down just a little, I hit the minus paddle and shift into third gear, maintaing my speed and keeping the engine RPM up in the power band of 2,500 to 3,000 RPM.

This method requires more driver input and attention to the road, but it gets me about three more miles per gallon, compared to using the tow/haul feature. I get about 13 MPG using the tow/haul and about 16 MPG when I use L and shift manually up and down the hills. On flat roads I just use L and let it cruise in fifth gear. Doing this results in 2,100 RPM at 56- 57 MPH, my favored travel speed.

Try it and see if your mileage improves.
 

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The tow haul mode increases the line peressure in the transmission. This is done to keep the transmission from failing. Tow Haul has nothing to do with your millage it's sole purpose is to protect the transmission. You can still use the L setting in tow haul mode as Manu of us do to get the right gear for hills.

You should never tow without the button engaged. As well as the transmission tow haul increases the power out put of the alternator to supply additional power out to the trailer.

Keep doing what you are doing and you will eventually damage the transmission.
 

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he makes a good point about the alternator.
In D or L- the alternators output is controlled by the computer. if it doesnt need power- it cuts back output..

When you press the tow haul button- it defaults the alternator to increase output and not to limit it...
this is useful for those that have a 'camper' that has its own battery wich can be recharged with the electrical connections on the factory tow option.
 

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Discussion Starter #4
I was not aware the line pressure in the transmission was increased when using tow/haul. Where does this information come from? I find nothing in the owners manual about it. I thought the only thing tow/haul did for the transmission was to change the shift points to provide higher RPM's and therefore higher torque.

I will try using the tow/haul mode while in L and see how that works for me. I have no need for the increased charging capacity while in tow/haul because my trailer has 2 100 watt solar panels on top that keep my battery bank fully charged. I also have a xantrex smart battery charger that helps a lot.
 

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The line preasue increase has been done for years now. It's increased to ensure the transmission shifts properly under the higher weight load. The shift points also adjust and basically shift sooner to keep the max power or torque points to help tow.

Cars with performance shift modes also will increase the line pressure but they maximize the shift points for max power and speed before the shift occurs.
 

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BigBlueTraverse said:
The shift points also adjust and basically shift sooner to keep the max power or torque points to help tow.
I've found that it seems to be the opposite. It seems to shift later as the RPM's are even higher than normal when it shifts.
 

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jwhjr said:
I've found that it seems to be the opposite. It seems to shift later as the RPM's are even higher than normal when it shifts.
I think he meant "downshift sooner". I read it first, and thought the same as you, that the transmission actually shifts up later, to keep the engine in the power band. But it also makes sense to say it shift sooner, if you are talking about downshifting for hils etc.

tomato / tomato :D
 

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Discussion Starter #8
Yes, using the tow/haul mode causes the transmission shift points to maintain higher RPM's, whether accelerating or decelerating. I think that is why using tow/haul decreases gas mileage. If you are not trying to increase your rate of acceleration the tow/haul mode just needlessly reduces gas mileage. However, when you are going up hills in tow/haul mode the transmission does not downshift until after you have started up the hill, thus loosing RPM, torque, and speed. There is no way tow/haul can anticipate an upcoming hill and downshift just prior to achieving upgrade, so as to maintain speed and increase RPM's immediately prior to heading up the hill. Downshifting manually, just prior to heading up the hill, using the paddle shifter while in L, requires less throttle depression, thus saving fuel.

I was unaware of the increased line pressure for the transmission while in tow/haul mode. I suppose this increased line pressure causes a higher volume of oil flow through the transmission oil cooler, thus providing greater cooling for the transmission? Where can I read about this from a GM source?

I will experiment with using tow/haul while in L during my next tow and see how it works. I can say that towing with the Traverse provides me with the most pleasant towing experience I have ever had with any other tow vehicle, and I attribute that primarily to the six speed transmission, which I have never had before. When towing, the more gears you have, the better.
 

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Discussion Starter #9
I would be interested in recommendations as to how best utilize the paddle shifters (the +/- buttons on the shifter) while towing a load. Why is it there? I know that one way it is used is to limit the highest gear the transmission can automatically shift into while the transmission is in L mode. Are the paddle shifters operational while in D, or are they only operable while in L? My impression is that these paddle shifters are functional only when in L.

Are there circumstances when it is best to shift manually rather that automatically, when towing in L? If so, please explain those circumstances. It seems to me that upshifting manually serves no purpose other that to limit the top gear the transmission can shift into automatically. Therefore, it seems to me that manually downshifting is the only way one can override the automatic shifting of the transmission, while towing in L. Are there circumstances where manually downshifting is superior to letting the transmission downshift automatically? I would think that downshifting immediately PRIOR to going up a hill would be one of those circumstances. No?

What effect, if any, does using the tow/haul mode have while driving in L, other than changing the transmission shift points and increasing line pressure? Can someone explain to me, in simple terms, how increasing line pressure benefits the transmission?
 

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I dont tow (yet),
But use L- and the +/- when im going to climb winding mtn roads locally.
Manually using +/- I can have control off the engine RPMs.
If its going down- I use it for engine braking mostly.

If its going uphill- there are times when you need higher RPM's and the right gear- this gives you a much better feel and faster response when you press on gas pedal. its a feeling that the higher RPM sort of slows down the vehicle when you let off the gas-- but at the same time press on the gas- and it accelerates immidiately.
something I find quite useful on the tight turns- (2 lane roads)
 

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Dear felpa41,

According the information that I have read in the 2011 Chevrolet Traverse owner's manual, the Electronic Range Select Mode is to be used when you put the vehicle the "L" (Low) position. This information can be found on page 1-16.

If you have not read the owner's manual, you will also find more specific information about the ERS Mode on page 9-26.

I hope that you have a great weekend!

Michelle, Chevrolet Customer Service
 

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Discussion Starter #12
Thanks Michelle. I just finished reading these areas of my owners manual. The paddle shifters, called Electronic Range Select (ERS) in the owners manual, is operable only when the transmission is in L. It is inoperable in D.

Here is a quote from the owners manual, page 9-26: "Automatic Engine Grade breaking is not available when the ERS is active. It is available in D (Drive) for both normal and Tow/Haul mode. While using the ERS, cruise control and the tow/haul mode can be used."

When I tow, I prefer to downshift manually. Therefore, I prefer to tow in L. While Automatic Engine Grade breaking is not available in L, MANUAL engine grade breaking IS available, via the ERS. I feel I can manage the downshifting of the transmission better than the computer, simply because I can see the road ahead and the computer can't.

I have never used tow/haul mode while towing in L, but I will try it the next time I tow. The only change I should notice is that the transmission will remain in lower gears a bit longer, keeping the RPM's higher and using more fuel. Since I am not trying to accelerate my rig as fast as most drivers prefer, I may choose not to use tow/haul mode in order to save fuel. I don't depress my accelerator more than the minimum that is required to get up to speed so I don't think I will cause my transmission to slip by allowing it to automatically upshift at a lower speed than the tow/haul would otherwise allow.

If anyone feels I may damage my transmission, towing in this manner, please let me know why. I went to the website "just answer.com" and asked a GM engineer about towing in this manner. He told me he thought that it would be fine, but would not recommend it for the average driver because the average driver is not experienced enough to manually manage the selection of gears. For the average driver, the computer can do a better job of gear selection. For an experienced and conservative, in terms of speed and acceleration, driver, the computer is inferior to the driver when it comes to downshifting. This is because the computer can't see the road ahead and the driver can, so the driver can downshift prior to the computer, in anticipation of the hill that lies just ahead.

So, I withdraw my recommendation that drivers not use tow/haul mode. The average driver may not be experienced enough or be willing to accelerate at the slower rate that I am. By towing the way I do, I increase my towing gas mileage from about 13 MPG to about 16 MPG. I will carefully monitor the condition of my transmission oil to make sure it remains normal.

Your comments and suggestions are always welcome.
 

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felpa41 said:
I would be interested in recommendations as to how best utilize the paddle shifters (the +/- buttons on the shifter) while towing a load. Why is it there? I know that one way it is used is to limit the highest gear the transmission can automatically shift into while the transmission is in L mode. Are the paddle shifters operational while in D, or are they only operable while in L? My impression is that these paddle shifters are functional only when in L.

Are there circumstances when it is best to shift manually rather that automatically, when towing in L? If so, please explain those circumstances. It seems to me that upshifting manually serves no purpose other that to limit the top gear the transmission can shift into automatically. Therefore, it seems to me that manually downshifting is the only way one can override the automatic shifting of the transmission, while towing in L. Are there circumstances where manually downshifting is superior to letting the transmission downshift automatically? I would think that downshifting immediately PRIOR to going up a hill would be one of those circumstances. No?

What effect, if any, does using the tow/haul mode have while driving in L, other than changing the transmission shift points and increasing line pressure? Can someone explain to me, in simple terms, how increasing line pressure benefits the transmission?
I tow with tow/haul engaged and in "L" mode. The reason being, my trailer has a lot of frontal area and so my Traverse gets very sluggish when it shifts too early. Remember, drag is a bigger factor for the Traverse (or any tow vehicle) then weight.

When I see a hill coming up, I manually tap down the transmission to 4th or 3rd if required, because when the transmission down shifts, the RPM's flare up and then settle back down to where they should be. This is because when you down shift, to keep the shift smooth, the torque converter unlocks and a few seconds later re-locks in the new gear. For instance, when I am in 5th gear turning 2000RPM, if I tap down to 4th, the RPMs will flare up to 3000RPM, and a few seconds later they will drop to around 2600RPM.

I want this flare up to occur before I'm straining the transmission to get up the hill. By tapping down just before the hill, I can be assured that the torque converter is locked up, and I will generate very little heat in the transmission heading up the hill. Once I'm going up the incline, I tap the selector back up to 5th, that way at the top of the hill the transmission will up shift.

This method works really well for me. Whether I'm in tow/haul mode or not, I can get the transmission into 5th gear on the highway. Since I try very hard to avoid city driving, the mileage "loss" due to tow/haul is very minimal, plus I don't want my Traverse to start lugging.

Each situation is different. My trailer is in the 4800lbs area, plus has a large frontal area.
 

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Discussion Starter #14
Yes, aerodynamic drag is significant for many travel trailers. My trailer has a small frontal area, compared to most, and there are no square corners on my fiberglass, egg shaped trailer. The drag on my trailer is much less than the typical travel trailer. I do not need an anti-sway bar and I use a deadweight hitch. I get no noticable push/pull from the big 18 wheelers that pass me in the next lane as I did with other travel trailers I have towed.

I see you also manually downshift, at the bottom of the hills and don't wait for the computer to downshift after you have lost speed and RPM's. I think this is smart. I will try using tow/haul mode in L during my next tow, but I have not sensed a need for it yet because I can accelerate very adequately without it and without depressing the accelerator beyond the very minimum.
 

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Dear felpa41,

There is no need to thank me for providing you with information that may assist you with your situation. It is my pleasure to be on the forums and interacting with all of you. :)

The additional information of how you drive your Traverse was very interesting. I really enjoyed the information that you shared with us. :thumb:

Please, don't hesitate to contact me with questions and/or concerns that you may have in the future.

Sincerely,
Michelle, Chevrolet Customer Service
 

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1 very minor thing tow/haul does as well is with the turn signals. In a normal mode...if you just bump the turn signal it will flash 3 times automatically in the direction it was actuated. With tow/haul active it flashes 6 times. It does this assuming you have a trailer so it can blink longer while changing lanes
 

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There will be a difference in having an older Traverse with the 6-speed transmission as compared to a newer one with the 9-speed transmission. Tow Haul mode is designed to keep the transmission running cooler and it does that by keeping the torque converter clutch engaged longer before making an upshift and it changes the upshift points.

I would be careful about using manual or range select mode on a Chevy. My 2011 Chevy Silverado had grade control that worked very well when towing but it only worked in auto mode. Putting the transmission into manual select would shut off the GM grade control entirely.

Worrying about fuel economy when towing instead of damage to the transmission is foolish. A transmission failure can leave you and your trailer stuck on the side of the road if you are lucky or stuck in the middle of the road if you are not.
 
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