AN electric supercar was the stuff of dreams only a few years ago but now there's one ready for mass production courtesy of BMW.

The i8 is a technological force majeure combined with a feast of design.

It looks incredible, has a theoretical fuel economy of 135 miles to the gallon yet can knock off 0 to 60 in 4.4 seconds.

Moreover, it drives like a dream and sounds just like a sports car should.

It also costs the best part of £100,000 bar a few quid although the government will chip in with £5,000 because it's an electric car taking the price down to £94,845.

In a nutshell the i8 is a plug-in hybrid which means it is three cars in one.

It's got a petrol engine driving the rear wheels, an electric motor to power the front ones and bringing them together delivers 362bhp.

In a car with a body made entirely from carbon fibre and weighing in at just 1.49 tonnes that is a potent combination.

There is slingshot acceleration if needed, the top speed is regulated to 155mph yet such is the blend of power and efficiency that astonishing fuel economy as easily attainable.

Forget the headline figure - that's purely academic. In the real world 40mpg is realistic - more if you are clever with the drive systems.

Nevertheless emissions are just 49g/km making the i8 the most tax friendly supercar money can buy.

For a full blown performance machine up against the best Audi, Mercedes, Porsche and Jaguar have to offer those fuel figures are quite remarkable.

And this being BMW's flagship sports car the handling is top notch.

Fully charged the i8 has a range of some 23 miles purely as an electric vehicle where it has a top speed of 75mph and sounds more like a jet than a car under acceleration.

It starts up and moves off silently and in its normal configuration - there are four selectable drive modes - the petrol engine will cut in around 45mph at which point the car drives as a hybrid.

The engine, which is built in Britain at BMW's Hams Hall factory in Warwickshire, is just 1.5-litres yet with the help of twin turbos is boosted to 231bhp,

There is a 10 gallon fuel tank and realistically the i8 has a range of around 400 miles.

On the road the car can be switched out of its normal hybrid set up into a sports mode for maximum power from the engine, an eco mode which weans off energy sapping equipment such as the air conditioning or put into an EV mode to run purely on battery power.

In the sports mode in particular the engine braking is captured and used to recharge the batteries on the move and we found it possible to get the battery pack back up to more than 60 per cent capacity while driving, adding significant miles to the range.

It is a driving experience like no other - hugely satisfying in a techno way.

Fully recharging the battery from an external supply or the mains at home can take just two hours and cost a couple of pounds and the hook up point is located on the front nearside of the i8.

The lithium ion batteries are slung under the middle of the car helping to keep a low centre of gravity and with four wheel drive available when both power sources are working there is great grip and balance.

But not only is all this cutting edge for the driver it is also housed in a body that looks sensational.

The i8 was revealed in concept guise five years ago and little has changed since its debut at the Frankfurt Motor Show in 2009.

It is low slung at just 4ft 3ins high with classic sports car proportions of 6ft 4ins in width and 15ft 4ins long and is a crowd puller wherever it goes with its dihedral doors swinging up from the body.

Although there are four seats leg room in the back is minimal and the boot below the lift up rear window is tiny - just a couple of overnight bags and that's the lot.

Bring the rear seats into play for luggage and think of it as a two-seater and it has to be the ultimate way of touring in a car of the future.

The cockpit is as splendid as every other aspect, intimate yet for such a complex piece of kit very intuitive. There's a head up display, paddle shifters for the eight speed auto box and power flow graphics to scroll through on the central information screen.

Immediate information about how the car is working is shown on the instrument panel below the high tech speedo and rev counter which change colour to reflect the selected drive mode but from the driver's perspective there is no doubt that this is a car like no other.

And being part of BMW's new i family of electric vehicles there's some jargon as well. The upper bits are referred to as the life module while the underpinnings of the i8 are known as the drive module.

Other facets of BMW's i world include membership of a privilege club offering access to VIP gourmet and travel experiences which are probably more de rigueur than sweeteners to those who want to be at the forefront of a new generation of motoring.

The i8 is a stunning piece of equipment. Not only is it the most practical application of electric technology in any car so far it is also the most advanced - and the best - BMW we have ever driven. Simply magnificent.