RV Fuel Cost Per Mile: A Complete Guide

Meta Description: Calculate exactly how much each mile costs in your RV, including fuel and expense overheads. Learn the formula for RV fuel cost per mile.

When you are planning a massive road trip, looking at a $1,500 fuel estimate can be overwhelming. A much more manageable and practical way to view your budget is to break it down into a single metric: Cost Per Mile.

Knowing your RV's exact fuel cost per mile allows you to make rapid, on-the-fly decisions. If you are debating a 40-mile detour to see a famous roadside attraction, knowing your cost per mile lets you calculate the exact price of that decision in seconds.

In this guide, we will teach you the simple formula to determine your pure fuel cost per mile, and how to calculate a "True Cost Per Mile" that factors in maintenance and tire wear.

Calculating Pure Fuel Cost Per Mile

To find your pure fuel cost per mile, you only need two pieces of information:

1. The current price of fuel per gallon.
2. Your RV's exact miles per gallon (MPG).

The Formula:
Price Per Gallon ÷ Miles Per Gallon = Cost Per Mile

Let's look at three examples using a fuel price of $3.50 per gallon:

• Class B Van (15 MPG): $3.50 ÷ 15 = $0.23 per mile
• Class C Motorhome (9 MPG): $3.50 ÷ 9 = $0.38 per mile
• Class A Motorhome (6 MPG): $3.50 ÷ 6 = $0.58 per mile

Using this metric, if you drive a Class A motorhome, every 100 miles you drive costs you $58 in pure fuel.

Why You Need Your Exact MPG

The manufacturer's stated MPG is almost always wrong. It is calculated in perfect conditions with an empty rig. To get an accurate cost per mile, you must calculate your actual MPG under a real travel load.

To do this manually:

1. Fill your tank until the pump clicks off. Write down your current odometer reading.
2. Drive normally until you have used at least half a tank.
3. Fill your tank again until it clicks off. Write down the number of gallons it took to fill up, and your new odometer reading.
4. Subtract the old odometer reading from the new one to get your miles driven.
5. Divide the miles driven by the gallons purchased. This is your true MPG.

Calculating True Cost Per Mile (With Maintenance)

Fuel isn't the only thing your RV consumes when it rolls down the highway. Every mile puts wear on your tires, brakes, and engine oil.

Commercial truck drivers track their "True Cost Per Mile" relentlessly. While RVers don't need to be quite as strict, adding a maintenance buffer to your fuel cost per mile is a wise budgeting strategy.

A good rule of thumb for motorhomes is to add $0.15 to $0.20 per mile to cover routine maintenance items (like oil changes, filters, and tire replacement over time).

So, taking our Class C motorhome example from above ($0.38 fuel cost per mile) and adding a $0.15 maintenance buffer brings the True Cost Per Mile to $0.53.