How do you compare fuel costs?

To compare fuel costs, you must calculate the cost per mile by dividing the price per gallon by your vehicle's miles per gallon (MPG).

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Fuel & Efficiency

Cost Comparison

Compare fuel costs across blends and economy figures.

Cost Comparison

Cost per Mile = Fuel Price ÷ MPG

Compare E85 vs regular gasoline costs based on MPG offset (typically a 25-30% loss of economy due to ethanol energy density).

Gasoline Price (per gallon):

E85 Price (per gallon):

Gasoline MPG:

Distance to Calculate (miles):

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Perform a calculation and click "Log Current Run" to save it for side-by-side comparison.

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About this tool

The BuildLockr fuel cost comparison calculator helps you accurately compare gas prices and efficiency. Use this tool to calculate your true cost per mile between regular gasoline and E85 or other fuel types. Whether you are daily driving or planning a road trip, this estimator considers MPG differences to show true savings. This helps drivers decide if switching to E85 actually saves them money at the pump.

How to Compare Fuel Costs

Fill out the Gasoline Price and Gasoline MPG fields to see the break-even E85 price.

Common Fuel Cost Questions

Why does fuel type affect price?

Different fuels like E85 have lower energy density than gasoline, meaning you will get lower MPG. Even if E85 is cheaper per gallon, the true cost per mile might be higher depending on the price gap.

Is E85 cheaper than regular gas?

It depends on the current price gap and your car's specific MPG loss on E85. Usually, E85 needs to be at least 25-30% cheaper per gallon than regular gasoline to break even.