Guide

Ethanol or gas: which pays off?

Ethanol is cheaper per litre but you burn more of it. The rule of thumb, and the exact break-even for your car.

The 70% rule

A flex car burns more ethanol than gas for the same distance. The usual rule of thumb: ethanol pays off when its price is below 70% of the gas price. With gas at 5.00 and ethanol at 3.40, ethanol costs 68% of gas: ethanol pays off.

The break-even of your own car

Your car has its own ratio. Divide your consumption on gas by your consumption on ethanol: at 7.0 L/100 km on gas and 9.8 L/100 km on ethanol, the break-even is 7.0 ÷ 9.8 = 71%. Ethanol pays off whenever it costs less than 71% of gas.

With Car Log

Set the car as Flex (ethanol / gas). When you enter a fill-up, type the price at the pump: the app compares it with your last gas or ethanol price, first by the 70% rule, then by the break-even measured on your own fill-ups once it knows enough. See Fuel log.