How much does towing reduce fuel economy?

Towing typically reduces fuel economy by 20-50% depending on the trailer weight, frontal area, and speed. A heavy caravan at motorway speeds can halve your MPG. Lighter trailers at moderate speeds may only reduce economy by 15-25%.

What speed should I tow at for best economy?

The most fuel-efficient towing speed is typically 50-55 mph. Aerodynamic drag increases with the square of speed, so going from 50 to 70 mph roughly doubles the drag penalty from the trailer. The legal limit for towing on motorways is 60 mph.

How does towing affect EV range?

Towing has a dramatic effect on EV range, typically reducing it by 30-50% or more. An EV with a 300-mile range might only achieve 150-180 miles towing. The heavier weight and increased drag require significantly more energy.

Does trailer weight or size matter more?

Both matter, but at higher speeds the frontal area (aerodynamic drag) becomes dominant. At lower speeds, weight (rolling resistance) is more important. A low, streamlined trailer causes less range loss than a tall, boxy one of the same weight.

Can I improve fuel economy while towing?

Yes: drive at moderate speeds (50-55 mph), maintain correct tyre pressures on both vehicle and trailer, remove unnecessary weight from the trailer, use a well-designed aerodynamic trailer cover, and avoid harsh acceleration.

CarCalcs

Towing Range Impact Calculator

See how towing a trailer or caravan affects your fuel economy and range.

Vehicle Type

Type of vehicle you drive

Unladen MPG

Fuel economy value to convert

Vehicle Weight

Kerb weight of tow vehicle

Trailer Weight

Gross weight including load

Trailer Frontal Area

Towing Speed

Weight or capacity related to towing

Fuel Price

Current price of fuel

How We Calculate This

This calculator uses physics-based modelling to estimate the impact of towing on fuel economy.

Key Factors

Aerodynamic drag: Proportional to drag coefficient x frontal area x speed squared
Rolling resistance: Proportional to total weight x resistance factor
Weight penalty: Heavier total mass requires more energy to maintain speed
Altitude gains: Additional energy needed to climb hills with extra weight

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Actual figures may vary based on driving conditions, vehicle specifications, and other factors.