Electric cars cost around half as much per mile to run as their petrol or diesel equivalents. Research done by Carwow found that for a fiver, you'll still be driving in an EV long after a 'normal' car has run out of fuel. With Tesco now giving away electricity to customers for free while they shop, the case for EVs continues to get stronger and stronger.

So, you've filled your car with a fiver worth of fuel; that's less than a gallon these days. How far will that get you – maybe 50 miles in an efficient petrol car, and probably a bit further in a modern diesel? But how far can that fiver take you when you convert it to electricity?

Well, Carwow has crunched the numbers and found that an EV will get you far further than a conventional car, and much, much further than public transport. Using the VW Golf because there are petrol, diesel and electric variants of it, the study found that a petrol version would go 49.6 miles in real-world conditions. An equivalent diesel would do a bit better and travel 56.5 miles.

But the star of the show is the e-Golf, which with £5 worth of electricity in the battery could go up to 102 miles. In terms of miles per pound (mpp) from fuel alone (therefore removing other costs from the equation), EVs typically come in at over 30mpp whereas a Ford Fiesta, for example, does just 9.3 miles per pound, demonstrating the running cost advantages of an EV. Factor in the potential savings in servicing and residual values, and total cost of ownership starts to look rather good.

To add even wider context, the study averaged out how far you could go on public transport for your crisp five pound note. Across the ten cities studied, the average was 20 miles on the train and a paltry 12.6 miles on the bus.

Charge your EV for free while you shop

Providing a potential shove to those teetering on the edge of jumping into the world of EVs is Tesco's latest wheeze. In case you didn't already know, as part of the supermarket's partnership with Volkswagen and PodPoint to install 2400 chargers across its UK stores, you can charge an EV for free while you do your weekly grocery shopping.

So far, over 100 Tesco stores have had PodPoints fitted.

VW has created a handy calculator which demonstrates just how much free juice you can get while you wrestle with the trolley and play chicken with wayward children in the aisle. For example, a survey by Volkswagen found that shoppers spent 50 minutes on average per week in the supermarket – and far more if said supermarket has recently been rearranged. During this time, the 7kW chargers will juice an EV enough to cover around 22.5 miles.

Over the course of a year this works out at a not-too-shabby 1170 miles, or the equivalent of around 10 laps of the M25. In November alone the chargers that are already available delivered enough free energy to power an e-Golf for 250,000 miles. Given that the Tesco PodPoints are supplied by electricity from renewables, and the deal is that little bit sweeter.

Have a play with the calculator and see how far you could go.

There are plenty of businesses and locations such as other supermarket chains and shopping centres where you can charge for free while you shop. Check out Zap-Map's interactive map, through which you can filter to find out where free to use chargers are located.

Discover EV's take

One of the barriers to EV adoption is the outlay required to buy one. Understanding just how much cheaper they are to run, the low total cost of ownership and fantastic residuals is a message that anyone thinking about buying an EV should know about! When it comes to the Tesco scheme, well it's just yet another reason why EVs are such a good choice nowadays.

Of course, EV drivers benefitting from this will have to spend money in-store to get their 'free' electricity, but bearing in mind groceries are just part of every day life, it's money that's essentially already spent. And more to the point, it's not like any supermarket is giving out free petrol. These free electricity schemes won't be around forever, though.