Can we talk about efficiency again?

Miles per kWh isn’t a naughty phrase

Introduction

I love EVs. They are 100% the future of personal transportation as they can run cleaner and cheaper than ICE vehicles. EV brands have been quick to latch themselves on to this vision one way or another. Rivian and Lucid talk about sustainable luxury and how they are inspiring people to live a more sustainable lifestyle. Tesla likes to boast about the savings their owners get from driving an EV. Yet, for all the planet saving and wallet saving EVs can do, we never talk about their objective efficiency to go from point A to point B which is… strange? We’ve been focused on miles-per-gallon for the longest time but when EVs came along we simply stopped considering efficiency. Unfortunately, the taboo nature of efficiency leaves out important information for the average car buyer. Now that EVs have matured past infancy, manufacturers and auto journalists should refocus the attention on efficiency.

What we see now and how we got here

Go shop for any EV nowadays and you’re likely to come across several standard performance metrics:

• Range
• Horsepower and torque
• 0-60 time
• Opaque estimates for typical gas savings

But why these metrics? Why isn’t efficiency included here? Some potential reasons could be:

1. In the early days of EVs, manufacturers likely did not want to confuse consumers more than they had to, so they only presented information they were used to seeing with ICE vehicles.
2. Most people implicitly assume that EVs are efficient, regardless of their form factor or design (looking at you Hummer EV or Silverado EV).
3. Consumers are mostly worried about range when it comes to EVs and rightfully so. Many early EVs were poor vehicles for the average American.
4. There simply have not been enough EVs on the market to make comparing efficiency between EVs worth it. Moreover, comparing EVs to gas vehicles has seemed confusing and difficult to generalize given how electricity and gas prices vary so much area-to-area.

Why we should bring efficiency back into the conversation

It may not have been a bad idea to exclude efficiency from early discussions on EVs, but the market has matured, and consumers have become more familiar with how EVs work. It’s time we bring back efficiency, miles per kWh, for several reasons:

1. Consumers really do care about efficiency. In fact, according to Statista, 52% of car buyers consider fuel efficiency “especially important” when buying a car. They should – fuel makes up a large portion of the total cost of ownership for a vehicle.
2. Consumers got used to MPG and they can get used to miles per kWh too. Ask nearly anyone and they will be able to explain how to calculate MPG. MPkWh isn’t all that different.
3. Some EVs are a whole lot more efficient than others and will be a lot cheaper to run / a lot better for the planet. Take the Tesla Model 3, Rivian R1S, and Kia EV6 for example. Driving each for 100 miles at $0.20 per kWh yields very different total costs.

Model 3: ~4 miles per kWh (2023, RWD) -> $5 to go 100 miles. Rivian R1S: ~1.9 miles per kWh (2023, 20 inch wheels) -> $10.50 to go 100 miles which is more than double a Model 3. Kia EV6: ~3.6 miles per kWh (2023, Long Range RWD) -> $5.60 to go 100 miles         

4. Cost saving calculations are ultimately hyper local. Energy costs vary by region and by % of home vs. public charging. It will be up to the consumer to enter their specific numbers into a calculator to understand how much cheaper it will be for them to drive an EV. I suggest trying out my calculator if you’re unsure of what your savings are.

What efficiency data enables

Manufacturers should post the mile per kWh number front and center, not hidden away like it currently is on vehicle stickers and definitely not deprioritized behind the admittedly confusing MPGe.

With this information consumers can directly compare EVs as well as ICE vehicles in terms of their annual energy cost.

A new vehicle buyer may reasonably consider two electric crossover SUVs in their search, a Ford Mach-E and a Tesla Model Y, and want to compare the efficiency of the two. The first number they will find today is the MPGe for both, 93 and 123 respectively. What does that intuitively mean though? How do they convert that easily to how much they'll spend in power that year? If, instead, each manufacturer plainly communicates the miles per kWh, the buyer can quickly calculate the difference in cost between the two models. For these models, that is 2.8 and 3.6 respectively. The average buyer can easily then take their annual driving amount, say 10,000 miles, divide that by the respective efficiency rating, and multiply by their cost of energy to get to a simple answer for energy cost. Perhaps they want to throw in a Honda CR-V for good measure. Calculating the annual cost of fueling that has been done for decades at this point: total miles / MPG * cost per gallon = total cost.

Ultimately, manufacturers need to do more to push their efficiency metrics and educate consumers about their importance. Auto journalists too could do a better job at helping consumers understand how efficiency works in the world of EVs. At the very least, let's talk about efficiency again!