# Best towing speed?



## hertig (Mar 16, 2005)

Hello, when I tow at the speed limit (usually 70 or 75), my gas mileage drops to 8 MPG, and I have trouble getting up hills.  What would be the 'best' speed to tow at for gas mileage?  For power up hills?  If these are variable, how would I figure out what they would be for me, besides trial and error?


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## C Nash (Mar 16, 2005)

Best towing speed?

John IMO you have to stay under 55 for best MPG.  As for the power range it will vary with each engine and rear axle ratio.  I have found that listening to the engin you can pretty well tell at what rpm it performs best. headers, dual exhaust, mufflers such as flowmaster, kn air filters help on power in the lower range.  Might even want to check into a camshaft that is recommended for towing.  Some like the tornado device that goes under the throttle body or is yours port iinjected? Might want to ck into getting the computer reburned.  Don't think it can have a chip added.


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## jkill2001 (Mar 16, 2005)

Best towing speed?

in my motorhome i trailered at a avg speed of 60 and i got about 10mpg. up hills i did about 50 or 45.


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## ARCHER (Mar 16, 2005)

Best towing speed?

I drive about 60-65 while pulling my dolly/honda and on long inclines it will get down to about 45.  I try to avoid the real long mountain type hills because I know I'd slow way, way down.  I get about 6-7 MPG on average with the 454 gas engine in the ole 89 Winn Chieftain.  I've not tried any of the items Chelse spoke of but might see about them this summer.


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## Krazeehorse (Mar 17, 2005)

Best towing speed?

Does the 'ol vacuum gauge tell the truth?  Whenever you are pulling the most vacuum you are at peak efficiency?  When you stand on the throttle or are pulling a load such as a long hill, they fall off to extremely low readings.  So I think you might find your best speed by observing a vacuum gauge.


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## ARCHER (Mar 17, 2005)

Best towing speed?

Well, Krazeehorse, I don't know if I have a vacum gauge or not.  I do have one of those efficiency gauges on my dash that the needle will go from green, to yellow, to red meaning of course, green is the best efficency, etc.  I try to keep it in the green as much as possible but it will go into the red when I first start off from standstill until I get up to speed then it levels off into the green and while I am driving I try to keep it as close to the green as possible.     :laugh:


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## Poppa (Mar 17, 2005)

Best towing speed?

The magic number in Nellie belle is 55 to 60 :laugh: ,(440) she will average 5 to 6 unless I am in hilly country. Long inclines she wil drop to 45 there abouts.

Run her at 65 or so and I can pass everything but a gas station. I am going to install a set of headers in a month or so when the darn rain stops and hopefully if nothing else she picks up 1/2 a gallon and some more pulling power.


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## Kirk (Mar 17, 2005)

Best towing speed?

quote:when I tow at the speed limit (usually 70 or 75), my gas mileage drops to 8 MPG, 

When I firest began to travel via RV, the service manager at the local dealership told me that a good general rule for fuel consumption for any heavy rig is that once you reach the optimum speed for conservation, in most cases around 50 mph, each time you increase speed by 5 mph you will decrease the mpg by 10%. He said to figure this from whatever mpg you get at 50/55 for whatever you are driving and/or towing. In more than 30 years of RV travel I have found that to be pretty much true. With some of the modern RVs the optimum mpg is reached at a slightly higher speed, and the terrain you are traveling through will also effect the speed of greatest efficiency, but the rule is still a good guide. If you use that rule, then your mileage being 8mpg at 70, the figure backward to 55 you have to expect to get near 11mpg. I suspect that figure is pretty close. High speeds cost fuel in all vehicles and the big block engines we use for our heavy RVs are at the top of the consumption.


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## campbud (Mar 17, 2005)

Best towing speed?

I generally travel about 60-62mph. I get around 7-8 mpg. I dream of someday getting better but I think that is off in the distance... :laugh:


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## C Nash (Mar 17, 2005)

Best towing speed?

Archer, put an egg under your gas pedal and if you don't burst it you will get better gas milage. :laugh:  :laugh:  :laugh:


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## hertig (Mar 21, 2005)

Best towing speed?

Thanks to all for your advice.  I was thinking of slowing down to 60-65, but the consensus seems to be that 50-55 might be better.  I'm going to see if I can get an add-on 'efficiency guage'; that might be the best way to find the best compromise.

Chelse, the truck came with the towing package, so hopefully the cam is appropriate.  It is port injected.


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## C Nash (Mar 22, 2005)

Best towing speed?

woops hit post twice :blush:


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## C Nash (Mar 22, 2005)

Best towing speed?

John the towing cams come in aftermarket.  A vacuum guage would help you keep the engine in it's confort zone for the best mpg.  Doesen't improve MPG just helps you drive your best for MPG. Just give 50 a try and you will see an inprovement and don't try to get to the top of those hills ahead of those 
Found 
On 
Road 
Dead vehicles :laugh:  :laugh:  :laugh:


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## Poppa (Mar 23, 2005)

Best towing speed?

One other thing to mention as far as fuel consumption, if you allow your rig to slow climbing hills your fuel consumption won't be as bad as if you try to maintain the same speed going up an incline.

If you have a cruise control set it on 55 to 60 and just let it laizily eat up the highway.


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## Krazeehorse (Mar 23, 2005)

Best towing speed?

Hertig, just practice up on your poker game.  That should be easy since it's on tv all the time now.  Then get in a friendly little game at the campground, win an extra $40 or $50 and drive as fast as you want!  :laugh:


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## hertig (Mar 24, 2005)

Best towing speed?

Sorry, I don't gamble.  Its not a matter of not having the money for a few extra gallons of gas, just a deep reluctance to spend it     I didn't get a 40% raise last year, so why should the oil industry...


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## sirhuntalot (Mar 25, 2005)

Best towing speed?

Hertig 
 I get the same as u on my 2003 2500HD 6.0 / 4.10's  Im running 285's tires on mine, but that 6.0 sure pulls good doesnt it? :laugh:


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## hertig (Mar 28, 2005)

Best towing speed?

Pulls great on the flats.  Has trouble pulling up any incline...


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## Russc (Apr 2, 2005)

Best towing speed?

I did some testing with my truck (see sig) and different driving techniques. I found that driving 60 mph (steadliy as possible) saved me from 4 to 7 mpg versus trying to keep up with traffic flow (interstate) say at 68 to 70 mph.

Not to mention the safety factor at slower speeds.  Also keeping the tires properly inflated on both TV and RV will save an average of 1 to 3 mpg. Someone posted, (with back up evidence, do not remember the source), that an improperly inflated tire can cost from 1 to 3 mpg. 

Food for thought, especially now!!!


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## Four Winds (Apr 3, 2005)

Best towing speed?

We have been driving a 2000 Four Winds class C with a 454 for about 3 yrs now. I find that if I keep the speed at 60 or less I can pull about 10 mpg except in mountains. We found that we also saw a lot more scenery and enjoyed the trip more. We also found that coming home from Montana to Michigan this past Oct driving at 60 so we moved it up to about 65/70. The mileage took a hit but we kept our sanity. The big plus for us was enjoying our trips a lot more when we took it slower. I am also very watchful of cars behind me and will pull over as soon as I can so they can pass.


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## the_vfox (Apr 9, 2005)

Best towing speed?

We tow at 60, get 10 to 14 depending on wind terrain etc. My D/A holds that speed on all but the steepest of grades.


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## hertig (May 12, 2005)

Best towing speed?

OK, here are the results so far.  (Running at the speed limit, 70 and 75, I got 8.2 MPG).  From Arizona to Texas, I ran with the cruize control set at 60 MPH, and Tow/Haul mode on (when I remembered  and gas mileage averaged 9.8.  From Texas to Illinois I ran at 55 MPH and averaged 10.2 MPG, a 25% increase, not too shabby.  

Also, being the 'slowest thing on the road' was much less stressful (on me at least   )  Plus I almost never had to slow down for slower people, reduced speed zones or construction.  And the rig seemed to go up hills more easily (haven't hit any really good ones yet, though).


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