Pulling a trailer takes more fuel, often a lot more. A light utility trailer might cost you around 15% of your gas mileage; a tall travel trailer or fifth wheel can take a third or more. The trailer’s shape matters as much as its weight.
What towing does to a 1,000-mile trip
This example uses a pickup that gets 18 MPG on its own and this week’s average gas price of $4.284. Without a trailer, 1,000 miles costs about $238 in fuel.
| Towing | MPG drop | MPG while towing | Fuel for 1,000 miles | Extra cost |
|---|---|---|---|---|
| Not towing | about 0% | 18 | $238 | +$0 |
| Light trailer, under 3,500 lb | about 15% | 15.3 | $280 | +$42 |
| Mid-size trailer, 3,500 to 7,000 lb | about 25% | 13.5 | $317 | +$79 |
| Large trailer or fifth wheel, over 7,000 lb | about 35% | 11.7 | $366 | +$128 |
These percentages are the rough reductions the RV and towing calculator uses. Your own numbers can land on either side of them, which is why it pays to measure.
Why a trailer costs so much fuel
Weight is part of it: the engine has to accelerate and climb with more mass behind it. But at highway speed the bigger factor is air. A travel trailer is usually taller and wider than the truck pulling it, so it presents a large flat face to the wind, and wind resistance rises steeply as speed goes up. That’s why a heavy but low flatbed can be cheaper to tow than a lighter but tall camper, and why slowing down helps more when you’re towing than when you’re not.
How to tow on less fuel
- Drive slower. Dropping from 70 to 60 mph is often the single biggest saving when towing a tall trailer.
- Travel with empty water tanks and fill up near the campsite. Water weighs about 8.3 pounds per gallon.
- Keep tires on the truck and trailer at the recommended pressure, checked cold.
- Use a weight-distribution hitch and load the trailer evenly so it tracks straight and doesn’t sway.
- Plan routes around long mountain grades when there’s a reasonable alternative.
Measure your own towing MPG
Fill the tank, reset the trip meter and tow as you normally would. At the next fill-up, divide the miles driven by the gallons it took to refill. Do it over a few tanks, and do the same without the trailer. Comparing the two tells you exactly what towing costs your rig.
Put your own numbers in the RV and towing fuel calculator: choose your tow vehicle, pick the trailer size and enter the miles.
Sources and method
Fuel prices are weekly retail averages including taxes from the U.S. Energy Information Administration. Driving distances between cities come from OSRM using © OpenStreetMap contributors data. Fuel economy figures are typical real-world values that PumpTally uses as calculator starting points, not manufacturer ratings; your own vehicle may do better or worse. Every table on this page is recalculated each week when prices update.