How many miles per gallon can an EV do?

Weird question, right? EVs don't use gallons. Bear with us on this one, the answer is pretty interesting.

Miles Per Gallon (MPG). It's the number that tells you how much bang you're getting for your buck. And most of us know what good is in a petrol car. Less than 20 is pretty poor. 30-40 is OK. Over 50 and you’re doing well.

But then you go electric, and suddenly that simple number is gone, and you're left with a question - how many miles per gallon am I getting, in "old money"?

That got us thinking. Instead of asking people to learn a new language, why don’t we just put things in terms that people already understand?

So, we've created a new measure: Miles Per Gallon electric (MPGe). It’s the simplest way to see how much cheaper it is to run an EV compared to a petrol car.

(Actually we thought we’d invented MPGe. Turns out the Americans got there way back in 2010 - darn you US Environmental Protection Agency. But the US is far away, and clearly it never quite made 'its' MPGe across the Atlantic. So we're taking it, like tea, but in reverse.)

MPGe (miles per gallon electric) is how many miles an EV will go for the cost of one gallon of petrol.

Let's do the maths, step by step. Here's an example for someone who does all of their charging at home:

Not bad - 356 miles per gallon!

Suddenly, your 30 MPG petrol car is directly comparable to your EV's 350 MPGe! Now that's what we call an efficiency jump. More of a leap.

Here is the MPGe for a handful of the UK's top selling electric cars, for 3 different charging scenarios.

• When you charge your EV exclusively at home, you can expect 8-11 times better MPG for your EV.
• For a mix of home and public, it's still a very attractive 2-3 times better.
• Even if you rely entirely on public charging, the worst case scenario is pretty much parity.

So next time someone says "But EVs, they're too expensive for me", introduce them to MPGe.

Not everything yet. We'll start using MPGe with a few EVs we offer. You'll see that start popping up on our website and emails. If people like it, we'll start making it standard.

The maths bit.

Here's what we've used to calculate MPGe.

• Cost of electricity
  • Home only: Intelligent Octopus Go - EV Saver tariff, 6p per kWh.
  • Public only: - 80% Slow / Fast, 52p per kWh, 20% Rapid / Ultra Rapid, 76p per kWh.
  • Mix: 80% at home, 6p per kWh, 20% Rapid / Ultra Rapid, 76p per kWh
• Efficiency - We have used the EVDB 'Real Range' figures, which represent a realistic mix of weather conditions, road types and driving styles.

The compliance bit...

• These calculations are correct at time of publication but are subject to change if energy prices change on Octopus Energy's Intelligent Octopus Go - EV Saver tariff.
• The number of miles any vehicle can attain varies and depends on a number of factors including the make and model of electric vehicle, the weather conditions and driving style.