Gas mileage with toad

[Peggyy]

So if i am getting 10 mpg on my class A, how much less will I get if I start pulling a toad?

 

[nfredrick]

probably depends on the weight , most people figure about .5 mpg  less....I didn't notice any difference  with my Honda Fit  last year behind my Class A

 

[missnmountains]

Absolutely no difference for us. Hills and wind make a bigger difference.

Ken

 

[Gary RV_Wizard]

The traditional wisdom has always been 0.5 mpg, but I think the number applies only to smaller, lighter coaches where adding a toad is a significant increase in weight and wind resistance. When we towed a 3800 lb toad behind a 17,000 lb gas chassis coach, there was an mpg decrease of 0.25-0.40.  But a 5000 lb toad had little impact on our 36,000 lb diesel pusher.  Plus there are variations with the size, shape & weight of the toad.

The science is that towing puts 4 more tires on the ground and their rolling resistance is a factor.  Further, the extra weight of the toad has to be carried up each & every grade. Finally, the frontal area of the toad has some affect on wind resistance, though that is mitigated somewhat by being shielded directly behind the coach.  That all means that heavy or tall or wide vehicles with big grippy tires probably have a greater impact than small cars with modest tires.  I 've not seen any data on those factors, though.

 

[John From Detroit]

I would expect 0-1 MPG difference. My first towed was a 4000 pound mini man and frankly the MPG meter could not tell if it was there. My new towed is 2500 pounds and costs me 1MPG.. Go figure.. and yes I do know why that is but explaining it.. Well...

The original had an axle lock so we towed with the tranny in park, next to no "Drag" from the drive train. the new one uses a lube pump so the tranny is "Dragging"

Differences in teh air flow over the towed.

 

[Kevin Means]

Our Jeep weighs about 4700 lbs and our RV weighs in about 40,000 lbs. We regularly climb many miles of 6% grades, and I've paid fairly close attention to the mileage over the years (Just out of curiosity.) I've noticed about a .2 decrease in mileage when we're towing - from about 7.3 to 7.1 (on average.) I would think that there would be a somewhat greater impact on a lighter RV towing the same weight vehicle.

Kev

 

[John Stephens]

I towed a sedan on a dolly for three years and saw about a 1mpg difference. I went to an SUV being flat towed this year and so far, have noticed only a .2mpg difference while driving in flat lands in Florida. I'll get the real test in another 45 days when we head to the Rockies, but I really don't expect to see any more than a .5 difference.

 

[Arch Hoagland]

About .5mpg for me. 

But there is another way to look at it.  I get 7 mpg but with a toad I figure I get 14 mpg.  Two vehicles get to the same spot for the same amount of gas.
I'm thinking of pulling two toads to increase my mpg to 21.

 

[Lou Schneider]

At 7 mpg, you'll use 14.3 gallons per 100 miles, a 0.5 mpg decrease means you'll use 14.8 gallons over the same 100 miles.  Plug in your actual mpgs for different scenarios.

To put it another way, in the example above the toad is getting 200 mpg being towed in the wind shadow of the motorhome versus whatever it's mpg would be be if it was driven solo.