Why MPG should matter for electric vehicles

If saving the environment is merely a lifestyle choice, the automakers and their latest electric vehicles have got us covered. Tesla’s Plaid touts performance. Leafs, Priuses and Volts preach humility. And Ford is flexing its muscle with launches of electric Mustangs and F-150s.

But if consumers’ choices are going to contribute to a greener future — if they’re going to opt for energy efficiency over flash — they need the ability to make smart purchasing decisions. To enable that, an old-fashioned measuring stick from the gasoline era could come in handy: the concept of miles per gallon.

In the electric vehicle (EV) era, car shopping is no longer a simple matter of finding a high-MPG car and a cheap gallon of gas. Electricity costs are confusing. Price and efficiency information is hard to find and harder to understand. And ultimately, you have to do the math.

That means getting to know electric energy’s unit of choice: the kilowatt-hour, or kWh — a string of characters better suited to an engineering textbook. To determine their costs and carbon footprints, drivers must solve the brain teasers that turn kWh into dollars and miles.

If you don’t do that, you’re trusting the automakers to do the right thing for you and the environment.

The government can lead on this problem. In fact, it has, and it does. Gas pumps have long been required to list the price of a gallon, gallons pumped and total fill-up cost. A vehicle’s EPA-mandated miles-per-gallon rating — displayed on dashboards and on every new car’s MPG sticker — ties it all together.

So maybe we already have a common denominator for the EV age. A familiar, tangible energy unit that gives us an apples-to-apples way to think about cost, efficiency and pollution.

Fellow Americans, say hello — again — to the gallon. Even as we leave the gas-powered car behind, we can keep its energy unit. It’s tangible, and if it works for the energy contained in gas, we can make it work for electricity.

According to the Environmental Protection Agency, a gallon of unleaded gas contains about 34 kWh of energy. Knowing that, you can easily deduce how much your energy purchase costs and how far it can take you. The gallon can even help you better understand your other electricity usage, putting your home energy costs on an apples-to-apples basis with your automobile’s energy costs.

When I gallon-ized my energy bills for the month of August, I learned:

  • My house used 56 gallons (1,888 kWh) worth of electricity.
  • My average home electricity cost was $6.34 per gallon.
  • At a Tesla supercharger, I paid $8.43 per gallon (25 cents per kWh).

The government already publishes an MPG equivalent for electric and hybrid vehicles. Using MPG, it becomes clear that electric vehicles make up for a lot of that high cost-per-gallon in efficiency, often with ratings over 100 MPG.

MPG is already good for more than car shopping. New York City’s MPG mandates have doubled taxis’ fuel efficiency since 2009. (The city also reserves a portion of taxi licenses — medallions — for hybrids.) Uber and Lyft have announced green initiatives, but their lightly regulated status has let them avoid MPG standards.

Smart energy shopping alone will not solve climate change. Energy watchdogs also need to monitor the industry’s carbon impact from both electricity generation and EV-related hardware manufacturing.

All else equal, though, using less energy means less pollution. And common units can steer us toward smart choices that encompass far more than our cars. Should I buy batteries so I can stock up on electricity when it’s cheapest? Do solar panels make sense? What about better insulation or more efficient appliances?

A high-MPG vehicle and a home that also goes a long way on a gallon? Together, that would be a solid lifestyle choice.