Fuel efficiency vs fuel economy

Fuel efficiency and fuel economy are two phrases that are often used interchangeably but have different meanings. The core difference involves fuel efficiency discussing how well a car uses fuel (like gasoline or diesel) and fuel economy measures how much distance a car gets out of fuel. While the meanings are similar, there is a slight difference worth noting:[1]

Fuel efficiency is related to thermal efficiency, and describes how efficiently a car burns fuel. For example, a Volkswagen Golf TDI Bluemotion is the most fuel efficient production car in existence, getting over 70 miles per US gallon of diesel[2] (3.17 L/ 100 km). Generally, fuel efficient vehicles achieve high fuel economy.
Fuel economy refers to how far a car can go using a set amount of fuel, its measure is generally miles per gallon (mpg), or in electric vehicles, miles per gallon gasoline equivalent (MPGe). While vehicles that achieve high fuel economy are generally highly efficient, a hybrid like the first-generation Toyota Prius achieved high fuel economy using hybrid drive, but its gasoline engine is actually not as fuel efficient as the above mentioned VW Golf.


  1. MIT Engineering. (2015, Mar.7). What is the difference between fuel efficiency and economy? [Online]. Available: https://engineering.mit.edu/ask/what%E2%80%99s-difference-between-fuel-efficiency-and-fuel-economy
  2. Nikki Gordon-Bloomfield. (2015, Mar.7). Volkswagen Golf BlueMotion: High-MPG Diesel Is Forbidden Fruit For Us [Online]. Available: http://www.greencarreports.com/news/1085403_volkswagen-golf-bluemotion-high-mpg-diesel-is-forbidden-fruit-for-us

Authors and Editors

Jordan Hanania, James Jenden, Kailyn Stenhouse, Jason Donev