- Towing a trailer reduces fuel economy by 20% to 40% depending on trailer weight relative to vehicle weight.
- A half-ton pickup rated at 20 MPG typically drops to 10–12 MPG when towing a 5,000–7,000 lb trailer.
- The fuel cost of a 500-mile towing trip can be $66 to $110 more than the same trip without a trailer.
- Added weight and increased aerodynamic drag are the two primary factors driving the fuel economy reduction.
Data/ folder. Treat them as order-of-magnitude approximations.01 Why Towing Hurts Fuel Economy
Towing a trailer reduces fuel economy by roughly 20% to 40%, depending on trailer weight relative to the tow vehicle's weight. Towing increases the forces the engine must overcome, and the DOE identifies two primary mechanisms behind the loss:
DOE, Office of Energy Efficiency & Renewable Energy, "Driving More Efficiently," fueleconomy.gov- Added weight. Every 100 pounds of additional weight reduces fuel economy by approximately 1% to 2%. A 5,000 lb trailer represents a massive weight increase that the engine must accelerate and haul uphill.
- Increased aerodynamic drag. Trailers, especially tall or boxy ones, dramatically increase frontal area and disrupt the tow vehicle's aerodynamic profile. This can double or triple the aerodynamic drag at highway speeds.
At highway speeds, aerodynamic drag becomes the dominant factor. A large enclosed trailer can increase the effective frontal area by 50% or more, and because drag force increases with the square of speed, the penalty is especially severe at 65+ mph.
Aerodynamic drag equation: F = ½ ρ Cd A v²; general vehicle physics, not a measured Data/ file02 MPG Impact by Trailer Weight
The table below shows representative fuel economy reductions when towing different trailer weights with a typical half-ton pickup truck rated at 20 MPG (EPA combined, unloaded).
Illustrative values built from general vehicle physics and DOE towing guidance, not a measured Data/ file; base 20 MPG is EPA-rated combined fuel economy for an unloaded half-ton pickup| Trailer Type | Approx. Weight | Est. MPG While Towing | FE Reduction |
|---|---|---|---|
| Small utility trailer | 1,000–2,000 lbs | 16–18 | 10–20% |
| Boat on trailer | 2,500–4,000 lbs | 13–16 | 20–35% |
| Travel trailer (small) | 3,500–5,000 lbs | 12–14 | 30–40% |
| Travel trailer (mid) | 5,000–7,000 lbs | 10–12 | 40–50% |
| Large travel trailer / 5th wheel | 7,000–10,000 lbs | 8–10 | 50–60% |
The shape of the trailer matters as much as the weight. A flat, low utility trailer creates relatively little additional drag, while a tall enclosed trailer or a boat on a high trailer creates enormous aerodynamic resistance. Wind resistance alone can account for half of the total fuel economy penalty at highway speeds.
DOE, fueleconomy.gov; general vehicle aerodynamics, not a measured Data/ fileEstimate your vehicle's driving cost using official EPA fuel economy data.
Use the Calculator03 Fuel Cost of a Towing Trip
The fuel cost difference of towing is significant on any trip of meaningful length. The table below compares the fuel cost of a 500-mile trip with and without a trailer, using a half-ton pickup at $3.30 per gallon (EIA 2024 average retail regular gasoline price).
Calculated from representative towing MPG estimates and EIA gasoline price reference| Scenario | MPG | Gallons (500 mi) | Fuel Cost | Extra vs No Trailer |
|---|---|---|---|---|
| No trailer | 20 | 25.0 | $83 | — |
| Small utility (2,000 lbs) | 17 | 29.4 | $97 | $14 |
| Boat (3,500 lbs) | 14 | 35.7 | $118 | $35 |
| Travel trailer (5,000 lbs) | 12 | 41.7 | $138 | $55 |
| Large trailer (8,000 lbs) | 9 | 55.6 | $183 | $100 |
For a driver towing a travel trailer on a 1,000-mile round trip, the additional fuel cost is roughly $110 to $200 compared to driving the same truck empty. Drivers who tow frequently should factor this ongoing cost into their budgeting.
04 Differences by Vehicle Type
Different vehicle types experience different absolute and relative fuel economy reductions when towing. Vehicles with higher base fuel economy lose fewer gallons per mile in absolute terms but may experience a similar percentage reduction.
EPA/DOE Fuel Economy Guide database for base MPG by class; illustrative towing reductions from general vehicle physics| Tow Vehicle | Base MPG | Towing MPG (5,000 lb trailer) | FE Reduction |
|---|---|---|---|
| Midsize/Large SUV | 19.6 | 11–13 | 33–42% |
| Standard/Full-Size Pickup | 18.3 | 10–12 | 35–45% |
| Heavy-Duty Pickup | n/a | 10–12 | 25–38% |
Heavy-duty pickups experience a smaller percentage reduction when towing because their engines, transmissions, and axle ratios are designed for loaded operation. However, their lower baseline fuel economy (unloaded) means the absolute gallons-per-mile cost while towing is still high.
05 How to Minimize the Fuel Penalty
The DOE offers several recommendations for reducing fuel consumption while towing:
- Reduce speed. Towing amplifies the speed-FE relationship. Dropping from 70 to 60 mph while towing can improve fuel economy by 15% or more due to the dramatic reduction in aerodynamic drag.
- Minimize frontal area. Choose trailers with aerodynamic profiles when possible. Keep loads inside enclosed trailers rather than stacking items above the roofline.
- Check tire pressure. Both the tow vehicle and trailer tires should be at their recommended pressure. Low pressure increases rolling resistance, which is amplified by the heavier combined weight.
- Avoid unnecessary weight. Carry only what you need. Every 100 pounds removed from the trailer saves roughly 1–2% in fuel economy.
- Use cruise control on flat terrain. Maintaining a steady speed is more fuel-efficient than speed variations, though cruise control should be disabled on steep grades.
06 Data Sources
- DOE/EPA: FuelEconomy.gov – "Driving More Efficiently." fueleconomy.gov
- EPA/DOE: Fuel Economy Guide database, model years 2024–2025. fueleconomy.gov
- EIA: Weekly Retail Gasoline and Diesel Prices. eia.gov
Data/ folder. Actual fuel economy while towing varies significantly based on trailer weight and shape, vehicle type, terrain, wind conditions, speed, and driving style. EPA fuel economy ratings do not include towing conditions. Individual results may differ substantially from the estimates presented here.