We recently looked at the 12 worst electric vehicles (EVs) for efficiency on the US market in 2022. Comparing the efficiencies expressed in watt-hours per mile (Wh/mi), we found that although GM’s new Hummer EV at 607 Wh/mi was by far the least efficient. Nevertheless, its average electricity cost was still only half as much as a 25 mpg gasoline-powered vehicle (running on $4.00 per gallon gas) in its fuel cost per mile.
EV efficiency depends on a wide range of different factors including the size and weight of the vehicle and its aerodynamics and the ability of its electrical engineers to design and build a highly efficient battery pack, motor, inverters, and electronic control systems. The most efficient EVs are in the low to mid 200 Wh/mi range, while the least efficient are above 300 Wh/mi. Lower numbers are better when comparing EV efficiencies in Wh/mi.
The cost of electricity (in dollars per kilowatt-hours or $/kWh) varies greatly around the US. The lowest is Oklahoma at $0.09 per kWh, and the highest is Rhode Island at $0.23 per kWh (Hawaii is higher at $0.31 per kWh). For our study, we assume the EVs are charged at home and used an average rate of $0.13 per kWh for the electricity.
As before, to look at the efficiency of EVs on the US market, we divided the vehicle’s battery pack size by its published range to get the efficiency in Wh/mile. Then, we also looked at how much it would cost to fully charge the pack (understanding that most EV drivers probably will only use 80 percent of the pack before recharging) and then divided that cost by the estimated range to get a figure in $/mile.
We found that the very best EVs can travel on less than $0.03/mile, but that even the worst on our list of the most efficient EVs only cost about $0.04/mile— about a quarter of what a 25 mpg gasoline vehicle would cost at $4.00 per gallon.
This is our list of the 17 top 2022 EVs for efficiency—we chose 300 Wh/mi as a cutoff and looked at efficiencies better than that to make a list that is arranged from worst to best based upon Wh/mi. With gas prices through the roof, it’s obvious that EVs are becoming an increasingly attractive alternative.
Kevin Clemens is a Senior Editor with Battery Technology.