Believe the hype and most drivers switching from petrol to electric are picking a an EV with the longest range possible within their budget. After all, a longer range means less range anxiety and a lower reliance on the public charging system because you’ll be able to complete any trip and simply charge up at home.
Electricity may be cheap in comparison to diesel or petrol (mainly due to the tax levied on liquid fuels), but that doesn’t stop some EVs using far more electricity than others.
Cost
One of the most efficient EVs you can buy today is the Tesla Model 3 Standard Range with an efficiency figure of 4.26 miles per kW, while the least efficient is the Mercedes QV300 at 2.3m/kWh.
That’s nearly a 50% difference which would translate directly into refuelling costs.
Run both of these cars for 20,000 miles and the difference in the electricity bill could be as much as £600 if you charge up at home. Do all your charging away from home and the difference could be as high as £1,200.
These two vehicles aren’t rivals but it gives an idea of the spread of efficiency in the same way that some petrol, or diesel, cars will struggle to break 30mpg while others will easily do more than 60mpg.
Efficiency
According to one expert, range isn’t necessarily the best point of focus, providing the car will allow the majority of a buyer’s journeys without having to charge up away from home.
In other words, if most of your journeys are, for example, less than 100 miles, then you only need a range above that figure to avoid having to charge on route. And you don’t want to do that because with home electricity typically costing around 15p a kWh and away from home charging costing typically 30p a kWh then your electricity costs can significantly
increase if you do fill up more away from home.
Looking why efficiency is important another way; if two cars charge at the same rate, the more efficient one will gain miles faster than the less efficient one because it will go further on the same amount of electricity.
While EV efficiency isn’t something buyers look at now – because moving from any petrol or diesel will save drivers money on fuel – once buyers are used to re-charging a car they will focus on efficiency much as drivers do for mpg now, according to EV expert James McKemey at charge point company Pod Point.
“At the moment we’re still talking about the switch from petrol and diesel to electric cars so they will always be more efficient. But once we’re used to using EVs it becomes interesting,” he said.
“For efficiency it’s important to understand your journeys because the cost of charging rises for plugging in on-route. You also have to remember that bigger batteries can take a higher peak [faster] charge than smaller batteries. If you’re doing longer journeys a larger battery car can charge quicker than a smaller battery car.”
McKemey believes knowledge of efficiency is important because it means drivers can go further on the same amount of electricity and therefore also gain miles quicker when charging.
He pointed out that at the same charging speed, a less efficient car may gain 18 miles in the same time it takes a more efficient car to gain 30 miles. He added: “As soon as you’re in an EV things suddenly concentrate on efficiency and you compare what you’re paying. People are used to comparing mpg, but in the future they’re going to compare EV efficiency.”
Depreciation
For the time being, however, it’s range that dominates car buyers’ thinking and this is reflected in the prices of used electric cars, according to valuations expert Rupert Pontin from Cazana.
Pontin’s examples comparing identical models but with different battery sizes shows that the cost of picking a smaller battery car in terms of the used car value currently far outweighs the amount saved by opting for the more efficient (and smaller battery) model even if all the charging was done away from home.
For example run two Hyundai Konas for two years and 20,000 miles, one with the larger 64kWh battery and one with the smaller 39kWh battery and due to the lighter weight and greater efficiency of the 39kWh car you’ll save between £30 and £60 depending on where you charge up.
Yet, according to Cazana, when you sell the 64kWh car it will be worth £572 more, far outweighing the any efficiency saving.
Of course, if you’ve bought your EV on a finance agreement with fixed monthly payments and don’t need to worry about the used car value, then efficiency once again becomes a factor.
Keyword: Which is better when buying an EV, greater range or better efficiency?