Since the 1970s, car manufacturers have been on a quest to find the Holy Grail of fuel efficiency. Even when gas was relatively cheap, they still had to meet government standards—and when gas gets expensive, buyers look more and more at that mpg number. Using less gas also means producing less air pollution, so a more fuel efficient car is also a greener car.
Here are the cars that will deliver you to your destination using as little gas as possible:
Toyota Prius Comes Out on Top
Your best bet for fuel efficiency right now is the family of Toyota Prius hybrids. The 2015 Prius Four, a four-door compact, is rated at 55 mpg on the highway, and 32 mpg in the city. Its siblings, the Prius C Two and Prius V Three come in a close to that at 48/47 mpg highway and 37/33 mpg city respectively.
Smart for Two Passion
Not surprisingly all the runner-ups are also hybrids (Honda Accord Hybrid, Lexus CT 200h Premium, Honda Civic Hybrid, Ford Fusion Hybrid) until you get to the Smart for Two Passion. On its 1.0 litre engine, this two-seater gets 44 mpg on the highway and 30 mpg in the city—almost equal to the Ford Fusion Hybrid.
Mitsubishi Mirage ES
After the Smart, there’s another string of hybrids (Toyota Camry Hybrid XLE, Ford C-MAX Hybrid SE, Volkswagen Jetta Hybrid SE) until you get to the Mitsubishi Mirage ES. On its 1.2 litre engine, it gets 47 mpg on the highway and 28 mpg in the city.
The lesson here is that if you want fuel efficiency, and you want some room in your car, hybrid is the way to go. But there are even more efficient cars you can buy: electric cars.
Gas vs. Electricity: Which Is More Efficient?
How do you compare the efficiency of gasoline vs. electricity? The U.S. Environmental Protection Agency (EPA) created the MGPe or “Miles Per Gallon (of Gasoline) Equivalent.” This takes the BTU’s contained in a gallon of gasoline (115,000) and measures them in terms of electricity.
When you plug this formula into the performance of electric cars, there are some amazing results. The Tesla Model S series gets you from 102 to 110 MPGe on the highway, and 64 or 65 MPGe in the city. Ford has also thrown its hat into the electric ring with the C-Max Energi, which delivers 98 highway and 87 city, and the Ford Focus Electric with 107 and 108 (better in the city than on the highway!).
Nissan and Mitsubishi are also in there. The Nissan Leaf SL is rated at 118 highway and 86 city and the Mitsubishi i-MiEV SE rates 116 highway and 104 city.
But the one that comes closest to finding the Holy Grail of fuel efficiency is…
…the mighty little BMW i3. On the highway, this subcompact can take you up to 141 miles on the equivalent of one gallon of gas, and 135 in the city. Of course the i3 will cost you $40,000, so you’ll have to decide where you want to save. Fuel efficiency comes at a cost: either size, or range, or sticker price.
And so the quest goes on for the Holy Grail of fuel efficiency, with manufacturers trying to meet government targets while also meeting customer demand. And, like King Arthur and his knights, there are also some idealists in there who seek this grail because they believe it will bring a better future.