Small RVs are the most fuel-efficient rentals you can book, but highway miles still add up faster than most first-timers expect. The good news is that a few driving habits move the number more than the vehicle itself. Here's what to plan for.
Highway vs. Around Town
An RV is a brick on wheels, so it rewards steady speed. Most small rentals return their best mileage in the 60-65 mph band. Drop below that and the engine works harder than it needs to; push past 70 and wind drag grows steeply. The difference between 60 and 75 mph can easily be 2-4 mpg on the same rig.
Realistic MPG by Type
These are typical ranges renters see, not lab numbers:
- Class B van conversions: about 14-20 mpg on the highway.
- Small Class C (20-25 ft): about 8-12 mpg.
- Pop-top / campervan: often at the top of the Class B range because of the lower profile.
Your actual result depends on payload, headwinds, and terrain. Mountain passes and a roof-loaded kayak both cost you.
A Quick Cost Example
Fuel cost per mile is your price per gallon divided by your MPG. At the U.S. average of about $4.08/gal for regular gasoline (U.S. Energy Information Administration, week of August 3, 2026) and 10 mpg, that is roughly $0.41 per mile. A 500-mile highway day is about $205 in fuel; a 1,000-mile leg is about $410 before campgrounds or tolls. Those figures move with the pump price — the EIA updates the national average every week, so check eia.gov/petroleum/gasdiesel for the current number and plug it into the RV Trip Budget Calculator for a full trip estimate.
How to Spend Less at the Pump
- Cruise at 60-65 mph. The single biggest lever.
- Check tire pressure at the rental pickup and top up if needed.
- Pack light and keep heavy items low and centered.
- Plan flatter routes when time allows; climbs burn extra fuel you don't recover on the way down.
None of this changes the trip, but together they can recover a few mpg and meaningfully lower the fuel line of your budget.