How much will a heavy trailer hurt MPG's

[bdog]

I need a trailer 25' long primarily to haul a couple UTV's on. Will be pulling it with a duramax dually.

I know these needs could be served by a light trailer even a bumper pull but I am considering buying a tandem dual gooseneck just because I could use it for other things. These trailers weigh around around 6k by themselves empty. How much would one of these hurt my fuel economy vs a light trailer? I often haul the UTV's all over the US for work.

 

[Diamondpilot]

I need a trailer 25' long primarily to haul a couple UTV's on. Will be pulling it with a duramax dually. I know these needs could be served by a light trailer even a bumper pull but I am considering buying a tandem dual gooseneck just because I could use it for other things. These trailers weigh around around 6k by themselves empty. How much would one of these hurt my fuel economy vs a light trailer? I often haul the UTV's all over the US for work.

I had a 25+5 GN that was 6,500# empty. I pulled it with a 99 F-350 Power a Stroke and a 05 3500 Dmax. Both trucks lost about 5 to 6 mpg pulling it empty. I sold that trailer and the Dmax for a 04 F250 then a 06 F350, both Power Strokes. I also sold the GN at that time and bought a 18' BP. In comparison the BP maybe lost 1 mpg pulling vs the GN losing 6 mpg.

Hope this helps.

Chris

 

[Cataclysm]

The short answer is a lot. I have a tandem dual 20k gvw GN and a tandem single 10K BP. Its night and day difference. 5 or 6 mph loss is going to be pretty close.

 

[4570Man]

A family member has a Dmax dually. He gets about 17-18 mpg empty ( which is a lot better than my 1/2 ton gasser ) and about 13 mpg pulling a 14 thousand pound camper.

 

[bdog]

Thanks. My dually (2016) has a flatbed with tools and stuff and weighs over 10k empty. It only gets around 15mpg empty due to the weight I assume. I have a stock 2016 3/4 ton duramax and it gets 18-19mpg empty.


If I could get double digits with the trailer I would be happy but I don't want to be in the single digits.

 

[4570Man]

If you hammer down on the gas pedal it would be possible to get in the single digits, but driving like a grandpa you can easily get 12 plus.

 

[CalG]

will doing more work take more energy?

Rocket science? Nahhh common sense

 

[bdog]

will doing more work take more energy?

Rocket science? Nahhh common sense

I know it will take more energy but I was wondering how much. Diesels seem to not take as much MPG hit as gas engines with loads. I can live with 2-3 less MPG with a heavy trailer vs a lighter one because it would be beneficial to me in other ways but if it is going to be much more than that I would probably be better off with two trailers because the UTV hauling could be a substantial amount of miles.

 

[CobyRupert]

Discounting the extra rolling friction (tire) which takes relatively VERY little extra fuel to overcome, and assuming we're talking about a flatbed trailer with little wind resistance, the only extra energy required is to accelerate the trailer up to speed and pull it up hills.

Now if you talking about a livestock, box trailer or camper trailer, then overcoming the extra air resistance takes the same extra fuel no matter what the trailer weighs and is only a function of your speed and additional surface area. Depending on the profile of the trailer, this can add a LOT of air resistance that needs to be overcome with extra fuel.

Imagine this: 2 trailers, same profile, same rolling resistance, but one weighs twice the other. If you were to drive 300 miles continuously on flat ground at the same speed with both, the only fuel difference would be what you used in the 1st 1/8 mile getting it up to speed.

 

[fordmantpw]

Discounting the extra rolling friction (tire) which takes relatively VERY little extra fuel to overcome, and assuming we're talking about a flatbed trailer with little wind resistance, the only extra energy required is to accelerate the trailer up to speed and pull it up hills.

Now if you talking about a livestock, box trailer or camper trailer, then overcoming the extra air resistance takes the same extra fuel no matter what the trailer weighs and is only a function of your speed and additional surface area. Depending on the profile of the trailer, this can add a LOT of air resistance that needs to be overcome with extra fuel.

Imagine this: 2 trailers, same profile, same rolling resistance, but one weighs twice the other. If you were to drive 300 miles continuously on flat ground at the same speed with both, the only fuel difference would be what you used in the 1st 1/8 mile getting it up to speed.

It's not just the friction of the tires, but also:

-- The added energy to get all of the tires and wheels rolling. There is a lot of inertia in tires rolling along at 65 MPH.
-- The energy to keep them rolling. The tires are constantly compressing all the way around, generating heat. This takes energy.

It takes a lot more energy than you think to overcome all the friction between the tires, bearings, etc. By switching to low-rolling-resistance tires, cars can easily gain 1-2 MPG. That's with 4 tires. Think of the difference of going from 2 or 4 to 8 (much heavier) tires and wheels with the tires being much heavier duty. If towing all over the US, I would say you would save enough fuel in a few years to buy that additional trailer, and you will have less wear and tear on your truck.