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-   -   Can someone explain Tow/haul mode.... (http://www.jeepgarage.org/f109/can-someone-explain-tow-haul-mode-57087.html)

spinxt 03-24-2013 01:45 PM

Can someone explain Tow/haul mode....
 
I have read the blurb in the manual and it barely makes sense to me. When I switch into tow/haul, the "D" indicator changed to "5" (almost like I and using the manumatic shifting option). Logic would tell you that selecting a lower gear number would hold you in that gear and help with descending hills.

Here's where I get confused, it specifically says in the manual NOT to use a lower gear for additional engine breaking.

Any thoughts? I understand all the stuff about disabling MDS, holding gears longer, etc. Where I get confused is when it starts talking about different gears that aren't used during normal driving mode.....

Alaska-HWY JK 03-24-2013 02:13 PM

Re: Can someone explain Tow/haul mode....
 
If you want to get 12/ mpg use tow haul mode.

spinxt 03-24-2013 02:18 PM

Re: Can someone explain Tow/haul mode....
 
That reply was a waste of both of our time.

2012 Summit 03-24-2013 02:29 PM

Re: Can someone explain Tow/haul mode....
 
Electronic Range Select (ERS) Operation
The Electronic Range Select (ERS) shift control allows the
driver to limit the highest available gear when the shift
lever is in the DRIVE position. For example, if you shift
the transmission into 3 (third gear), the transmission will
never shift above third gear, but will shift down into
second and first gear normally.
Use of ERS (or TOW/HAUL mode) also enables an
additional underdrive gear which is not normally used
during through-gear accelerations. This additional gear
can improve vehicle performance and cooling capability
when towing a trailer on certain grades. In ERS mode,
gears 1 though 3 are underdrive gears, and ERS 4 is direct
drive. ERS 5 and 6 (Overdrive gears ) are the same as the
normal fourth and fifth gears.
You can switch between DRIVE and ERS mode at any
vehicle speed. When the shift lever is in the DRIVE
position, the transmission will operate automatically,
shifting between all available gears. Tapping the shift
lever to the left (-) will activate ERS mode, display the
current gear in the instrument cluster, and maintain that
gear as the top available gear. Once in ERS mode, tapping
the shift lever to the left (-) or right (+) will change the top
available gear.
To exit ERS mode, simply press and hold the shift lever to
the right (+) until “D” is once again displayed in the shift
lever position indicator in the instrument cluster.

rich mac 03-24-2013 09:10 PM

Re: Can someone explain Tow/haul mode....
 
So.... Does that means quicker acceleration in tow mode?

kkreit01 04-02-2013 09:54 AM

Re: Can someone explain Tow/haul mode....
 
I know some people turn it off while "quickly accelerating". I don't know if it makes an actual difference. I thought it simply disable overdrive -- while towing up hills, etc. I've honestly never messed with it -- when I've had it.

ms.annthrope 04-02-2013 01:34 PM

Re: Can someone explain Tow/haul mode....
 
If you are towing a heavy load, using the Tow/Haul will direct the tranny to stay in gear longer before upshifting so as not to "lug" the engine--this give better pulling power as the lower gears are allowed to pull to high RPM before upshifting. Even if you are not towing a heavy load, 6,000+ pounds but carrying 4-5 people stuck behind an 18 wheeler or slow moving diesel pusher motorhome going 30 mph up a long steep hill, this feature will give more response and power than if the engine/trannyfrequently kicks up a gear then lugs then kicks down again.

If you also use the electronic tranny to downshift (ERS) along with Tow/Haul, it will lock the tranny to shift no higher than the selected gear, e.g., 3rd. This forces the engine to stay at higher RPMs to push more air through for better cooling and stay at peak torque band.

Gas engines have their peak torque at much higher RPMs than diesel, so using this feature is more beneficial if you are towing. Diesel engines can reach peak torque at 2,000 or lower so it can start moving the load right away instead of having to flog the squirrels to death.

Hope this helps.


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