Study: Superior Electric Vehicle Efficiency Not a Given

By: Ryan Gallagher December 4, 2017
Gas vehicles like the Ford Focus—which gets about 40 mpg highway—catching up to electric vehicles in efficiency in countries like the U.S., where the electricity grid is still heavily supplied with energy from fossil fuels.

The race between combustion engine cars and battery-powered vehicles is on. Electric vehicle (EV) manufacturers propose their technology is the greenest way to drive. But could a traditional gasoline-fueled vehicle ever match electric vehicle efficiency?

The answer: No… at least, not yet. However, gas-powered cars are slowly moving closer to electric cars on the efficiency scale, according to a new study from the University of Michigan Transportation Research Institute.

In the study, researchers measured the amount of fossil fuels needed to supply EVs with electricity, also known as “well-to-wheel” emissions. In many cases, it takes a coal or oil-burning power plant to supply EVs with the electricity they need to function. This means that at their root, these “fully electric” cars are still getting energy from fossil fuels. 

Researchers then compared the well-to-wheel emissions of EVs to those of traditional gas-powered cars, which include the fossil fuels needed to extract and transport the gasoline plus the amount of gas needed to power the car.

At the end of the study, researchers concluded that in order to produce fewer greenhouse gases than an EV, a combustion engine car would have to average 55.4 miles per gallon (mpg) in the United States. As of now, old and new cars in the U.S. average a fuel efficiency of about 22 mpg.

Brand new vehicles are becoming more fuel-efficient every year, though. In 2014 (the most recent year for which data is available), the average efficiency for new passenger cars was 36.4 mpg, according to the United States Department of Transportation.

And despite their current lead in the fuel efficiency space, cars running solely on a battery still have room for improvement extending beyond where their electric energy is sourced from. These vehicles often require much more energy to operate, and usually weigh much more than traditional combustion engine vehicles.

Additionally, EV producers often use non-renewable metals like copper, cobalt, and lithium for car batteries. Since EVs started taking off, researchers have predicted possible shortages of these resources if trends continue.

While more and more car manufacturers are coming up with electric solutions for a greener vehicle, these innovations have also created new efficiency questions. However, carmakers seem more than willing to innovate and spend on efficiency upgrades now, and ask questions later.

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