Help me understand... - Fiberglass RV


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-21-2013, 08:14 PM   #1
Senior Member
 
cpaharley2008's Avatar
 
Name: jim
Trailer: 2016 2ndGen Escape19 Prairie Schooner pulled by 2014 Dodge Ram Hemi Sport
Pennsylvania
Posts: 6,398
Registry
Help me understand...

Just came back from towing my Escape 19' with my Ram 1500 with the hemi engine and 5 speed automatic. I went 320 miles up and down mountains with my tow in "Tow mode" and got 10 mpg going up and down mountains, downshifting and rpms sometimes approaching 4000 rpm. On the return trip I kept the transmission in regular mode, got 12 mpg??? Not once did I go over 3000 rpm. Why the 20% difference and how come???
The manual says while towing to use this mode, but it really eats gas. Is it possible it is meant for a bigger trailer? Do I really need a tow mode with a trailer weight around 3000#?
I'm at lost for the difference. Same road down and back (not going to address the heading south is downhill and north is uphill issue)
Anyone explain?
__________________

__________________
cpaharley2008 is offline   Reply With Quote
Old 01-21-2013, 08:28 PM   #2
Senior Member
 
Name: Darwin
Trailer: 2002 19 ft Scamp 19 ft 5th Wheel
Posts: 3,030
Send a message via Yahoo to Darwin Maring
The tow mode locks it in a lower gear where the regular mode lets the Over Drive kick in. Most tow vehicles when in hilly country will shift down and up many many times and put extra wear on the transmission but in Tow mode it locks the OD out and it should not shift back and forth. If it does shift back and forth you may want to slow down and manually lock it in still a slower gear. We do this on the 7% grades (Mountains of West BG Virginia.
__________________

__________________
Darwin Maring is offline   Reply With Quote
Old 01-21-2013, 08:35 PM   #3
Senior Member
 
Name: Russ
Trailer: Scamp 16' side dinette, Airstream Safari 19'
California
Posts: 588
Harley,
To understand the difference you would have to read up on the "tow mode". Sometimes the overdrive is locked out in tow modes from various manufacturers. It is possible there are other computer controlled differences though, such as altering transmission shift points or retarding timing advance for loaded use. You'll have to read up on Chrysler's scheme.
Russ

In the end I would use whatever mode performs best though. Just listen for ping or detonation, as that can cause damage to your power plant. Do not allow it to ping.
__________________
ruscal is offline   Reply With Quote
Old 01-21-2013, 08:39 PM   #4
Senior Member
 
Name: Russ
Trailer: Scamp 16' side dinette, Airstream Safari 19'
California
Posts: 588
Also,
I asume you meant you averaged 10MPG going up and down the mountains. You must surely achieved greater MPG going downhill under lighter throttle. IE 8MPG going up and 12 going down.
__________________
ruscal is offline   Reply With Quote
Old 01-21-2013, 08:39 PM   #5
Moderator
 
Jim Bennett's Avatar
 
Name: Jim
Trailer: 2017 Escape 5.0 TA
Alberta
Posts: 4,727
Registry
There is likely no need to tow that light of a trailer in trailer mode with that big of an engine. With most trailers it keeps it out of overdrive.

When I tow with my Ford F250 with the Powerstroke diesel, my fuel economy barely changes when towing. It does not even notice the trailer behind it.
__________________
2017 Escape 5.0 TA (January 26)
2015 Ford F150 Lariat 3.5L EcoBoost
2009 Escape 19 (previous)
“Most folks are about as happy as they make up their minds to be.” — Abraham Lincoln
Jim Bennett is offline   Reply With Quote
Old 01-22-2013, 09:25 AM   #6
Senior Member
 
Name: george
Trailer: FunFinder
Missouri
Posts: 455
Jim,
I agree that the other responses have pretty well nailed it. I can tell you that on our F350 diesel, the tow/haul mode does in fact make it hold the lower gears longer as we accelerate, and also downshifts it sooner ( much sooner ) coming down the hill. Of course the downshift coming down is no fuel mileage penalty if you are totally off the throttle. But it is, when you press down on the pedal again.
It is likely or at least possible that your transmission temp was cooler while you were in tow/haul as compared to what it might have been when not. So that could be a potential tradeoff there....shorter transmission life vs more gas used.
These issues are part of why I like the manual trans in my Nissan, but that is not relevant to this discussion.
Does Dodge give a specific weight recco as for when you are required to turn on tow mode ? If so, I would likely go with that.

EDIT: I don't know what year your hemi is, but the earlier ones were pretty much known for liking lots of gas. One of my buddies has a 2004 1500 hemi that he pulls a horse trailer with, and yes indeed, it burns some fuel. Pulls it nicely though.
__________________
gmw photos is offline   Reply With Quote
Old 01-22-2013, 09:31 AM   #7
Senior Member
 
cpaharley2008's Avatar
 
Name: jim
Trailer: 2016 2ndGen Escape19 Prairie Schooner pulled by 2014 Dodge Ram Hemi Sport
Pennsylvania
Posts: 6,398
Registry
All good answers. It appears the tow mode is generic and not weight specific. Possible with a heavier trailer it maybe necessary and more efficient. The shift points are different as well as it stays out of overdrive in the tow mode. In the regular mode, o/d kicks in and sometimes it shifts to the 4 cylinder mode "fuel saver mode". I monitor the trans temp and saw no difference going or coming back. Not too concerned with transmission life as the model came with a "lifetime power train warranty" offered in 2009 during the "bailout crisis". Just the fuel efficiency, I get 12 mpg towing or not it seems. But it screams when you put the pedal down, 400 HP!! Hhmm, I wonder if anyone drag races while towing a trailer???
Next up, monitoring the FJ Cruiser towing figures.
__________________
cpaharley2008 is offline   Reply With Quote
Old 01-22-2013, 10:38 AM   #8
Senior Member
 
Name: Bob Ruggles
Trailer: 2015 Escape 19 2012 Chevy Silverado
Michigan
Posts: 1,305
With our Chevy 1500 and 5.3 liter engine, I do not use tow haul with either the Kodiak or the Egg Camper. Over the road and non-towing the Chevy gets the same highway mpg as our previous Dodge 6.7 liter diesel. As for towing, the Chevy gets about 2-4 mpg less than the diesel while towing the Kodiak. Mpg with the Egg Camper ranges from 13 to 17 depending on hills, traffic, speed, wind, etc.
__________________
rgrugg is offline   Reply With Quote
Old 01-22-2013, 10:44 AM   #9
Senior Member
 
Name: george
Trailer: FunFinder
Missouri
Posts: 455
Heck yeah, if you're not seeing a difference in tranny temp, and if you don't "need" the predictive downshifting on hills that tow/haul may give you, then I would leave it in in normal mode and go for the gas mileage.
As someone else pointed out, the different car companies do it all somewhat differently. On our powerstroke Ford, even in tow/haul, it will select OD ( 5th ), even with a 15K pound trailer in tow if the computer thinks it can pull it.
__________________
gmw photos is offline   Reply With Quote
Old 01-22-2013, 06:12 PM   #10
Senior Member
 
Mike Magee's Avatar
 
Name: Michael
Trailer: Li'l Hauley
Oklahoma
Posts: 5,143
I think that as long as you're not detecting excessive, heat-generating torque converter slippage, you're probably fine in regular mode.
__________________
How much time do we have left? 2 Chr. 7:14
Mike Magee is offline   Reply With Quote
Old 01-22-2013, 08:51 PM   #11
Senior Member
 
Orlen Wolf's Avatar
 
Name: Orlen
Trailer: Eggcamper 2007 ('Wolf's Lair')
Colorado
Posts: 312
Jim

I also tow with a Ram 1500, a 2007 quad cab short bed, and do not use the tow/haul mode to tow the EggCamper except when on long uphill pulls like the eastbound run from Silverthorne CO to the tunnel on I-70 (about 7 miles of 6%+ grade). I do lock out the OD on occasion when descending long downgrades, often also downshifting to 2nd for compression braking.

I've towed the EggCamper over 30,000 miles now with the Dodge. It averages about 12-13 mpg in the mountains and about 16 on flat highways when towing. I have found that the best speed for economy is 62mph and the thing that kills mileage the most is a headwind. At 62mph the tach shows 1750 rpm.

I towed my brother in law's camper, a 27' stickie, about 3,500 miles and did use the tow/haul mode. Only got about 9mpg on a trip from DFW TX to Denver and a round trip from Denver to the IN/IL border. There wasn't much in the way of up or down on either trip. I found that in the tow/haul mode overdrive would not engage and the tach showed 2600rpm at 60mph. There was also a noticeable change in shift points. I won't tow that oversized brick again!

In short I don't think tow/haul or OD lockout mode gives you any benefit. Just put the Ram in drive, hit the cruise control and let the on-board computers sort it out.

I would be interested in the results of your FJ tests. Many years ago I towed with a FJ-55 Cruiser but the only thing stock on it was the rear bumper and doors. It would move anything you tied to it but fuel footage was abysmal.
__________________
Orlen Wolf is offline   Reply With Quote
Old 01-22-2013, 09:06 PM   #12
Senior Member
 
cpaharley2008's Avatar
 
Name: jim
Trailer: 2016 2ndGen Escape19 Prairie Schooner pulled by 2014 Dodge Ram Hemi Sport
Pennsylvania
Posts: 6,398
Registry
Thanks Orlen, I'll post my results.
__________________
cpaharley2008 is offline   Reply With Quote
Old 01-23-2013, 09:37 PM   #13
Senior Member
 
Name: Steve
Trailer: Scamp 13
California
Posts: 1,418
I would look at the specs for the motor and check what peak torque is. try to not run the motor higher than peak torque for best milage. I think you should be getting better mileage than what your getting. Do you have over size tires? Any time your running over 55mph your going to suck gas expotentially. Push it harder the worse it gets. I do not run in tow mode I only use it when running up hill on any grade you wouldn't want to walk up. Do you have GPS? check your speedometer and odometer against it to verify your actual mileage. My girlfriends jeep liberty came from the factory with the meters reading 5 mph too high and the odometer off it made accurate caculations very hard.
__________________
stevebaz is offline   Reply With Quote
Old 01-23-2013, 10:01 PM   #14
Senior Member
 
cpaharley2008's Avatar
 
Name: jim
Trailer: 2016 2ndGen Escape19 Prairie Schooner pulled by 2014 Dodge Ram Hemi Sport
Pennsylvania
Posts: 6,398
Registry
I think my rear is 3:55 and I do have 20" tires/rims.
__________________

__________________
cpaharley2008 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Women Will Understand, Men Should Memorize Cyndi B. Jokes, Stories & Tall Tales 2 11-09-2010 05:50 PM
RAT FUR..CAT DOESN'T UNDERSTAND Susan Tiller General Chat 12 04-23-2006 11:12 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:56 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.