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Delta E-4 Eco

Click to view picture gallery“I was expecting total silence. In fact,
  the pure electric coupe I
m piloting
  is making some unexpected noise —
  in full flow on Silverstone
s Stowe
  circuit it sounds like a cross between
  a supercharged milk float and an
  alien spacecraft
...”


WELCOME TO BRITAIN'S LATEST ELECTRIC SPORTS CAR: the Delta E-4, a car that's pretty much unique. It's a high-performance electric gullwing coupe with four full seats that's designed and built in the UK.

The E-4 is the creation of Delta Motorsport. Who, you may ask? Delta was set up by ex-Reynard employees some six years ago. It's a small (ten-man) operation concentrating on motorsport they built the F1 'pillion' two-seater, for example as well as developing prototypes and technology.

The E-4 is intended as a showcase of Delta's talents but having spent some time behind the wheel at Silverstone, I reckon it would be tragic if the E-4 didn't make it to market it truly has such a lot going for it.

“With 1,106lb ft of torque
available
instantaneously,
the E-4 is a bit quick.
Delta quotes a
0-60mph of 6.5 seconds
and it feels every bit
as fast as that:
you get a full shovel-load
of performance from
the off
...”
Let's start with the design. The striking shape is the work of British penman Steve Everitt (he previously styled the Hennessey Venom GT and Vemac RD180).

Don't know what you think but I reckon the E-4 is a real looker a vibrant mix of Volvo C30, Honda CR-Z and DeLorean. And not only does it work a treat visually but, with a Cd of 0.27, it's also aerodynamically fit.

The fit and finish is also superb; the panels are very high quality and free of any 'wobbles'. This is partly the result of one of the new technologies in the E-4 a way of forming carbon so that it can be pressed, rather than moulded. While the main structure is carbon, semi-structural panels like the front-end and doors are made of glass-fibre.

The main chassis/body tub weighs a mere 85kg just one third of what the equivalent in steel would weigh. To put that in perspective, the battery pack weighs fully 350kg over 35% of the total weight of the car (975kg).

The dramatic scissor doors work surprisingly well too. A touch of a button releases each big door, which rises up on gas struts. It may not be as easy to get into the E-4 as a normal car but it's so much easier than, say, a Lotus Evora. That's because you have infinite room above you as you get in and that applies equally to rear-seat passengers. Okay, there's no tilt mechanism on the front seats but tall adults can, nevertheless, enter the car in reasonable comfort.

And you can fit four real-world adults in the E-4. Up front, there's plenty of headroom for six-footers, and even in the back the roof will clear the heads of the lofty and lanky. Legroom is much tighter, though, and rear passengers may find their foot resting on the electric cut-off button not ideal. There's even a decent boot, accessed via the tailgate.

The driving position feels slightly strange because the floor is completely flat and the pedals are a little offset. But the 'driver interface' is great, with what looks like an iPad in the centre console (in actual fact it's a variation of the same touch-screen control pad you'll find in the Koenigsegg). From here you control pretty much everything; from the AirCon to the electric mirrors.

“Simply pressing the
‘D’ button on the dash
engages the drive.
There’s no gearbox.
All you have are
two electric motors —
one for each rear
wheel
...”
Simply pressing the 'D' button on the dash engages the drive. There's no gearbox. All you have are the two electric motors one for each rear wheel and a control system that directs different amounts of power to each one. This same system also acts as a differential and torque-vectoring system for dynamic stability.

There are no fewer than 3,168 air-cooled lithium-iron phosphate cells in the battery pack under the floor and they supply each electric motor with a lot of juice: up to 553lb ft of torque each!

No surprise, then, that the E-4 is a bit quick. I drove the two-motor Eco version (a quad-motor Sport version is on the cards but hasn't been built yet) and it's hot-hatch quick. Delta quotes a 0-60mph time of 6.5 seconds and it feels every bit as fast as that especially as the torque response is instantaneous, so you get a full shovel-load of performance from the off.

Considering that the E-4 is very much still a prototype, it drives amazingly well. The Eco version is rear-wheel drive only and is set up to drive like a sports car. The wishbone/coil-over suspension settings have been modelled on a computer, rather than honed by real-life experience (the cars are so new). Even so, someone clearly has a very clever computer programme because the E-4 handles extremely well.

There's some body roll, but not much. With the bulk of the weight sitting below the floor (Delta claims the centre of gravity is comparable to a single-seat racing car), the E-4 sticks to the tarmac like a limpet, carving into bends in a very Lotus-like way with hardly any trace of understeer.

The steering feel is unlike anything else I've ever driven. Although it's based on a proprietary system, the feel is weighty and chunky. It's not altogether a 'natural' feel but it certainly inspires plenty of confidence.

“The steering feel
is unlike anything else
I’ve ever driven.
Although it’s based on
a proprietary system,
the feel is weighty
and chunky.
It’s not altogether a
‘natural’ feel but it
certainly inspires plenty
of confidence
...”
As I said to start off with, the E-4 is not totally noiseless, but the eerie lack of engine revs allows the road surface to be heard all too clearly, as well as every little stone that pings up into the inner wheelarches.

The problem with all electric cars is range and refuelling time. By creating a lightweight, aerodynamic package, Delta has given itself a head start, and E-4 prototypes are currently achieving a very respectable 120 miles on a single charge and that's expected to rise to 140 miles. However, there's no escaping the eight hours it takes to fully recharge the E-4.

So what's the future for the Delta E-4? In theory you can buy one now but it would be "very expensive indeed". The intention is to find a manufacturing partner and lower the price. The E-4 has been designed to comply with full Type Approval, but it needs significant investment to make that happen. As many as 50,000 units per year could be built using the carbon press process, and Delta reports that there's already been lots of interest from industry.

Four prototypes are now running on UK roads (registered under the IVA system). If a low-volume constructor were to take on production, the target price could be as low as 60,000 if the cost of the battery pack can be brought down. That's still in Nissan GT-R and Porsche Cayman R territory though a very tough battleground.

As well as the Eco version I tested, Delta is planning a Sport model later this year. This will have four motors (one for each wheel, making it four-wheel drive) to dish up an unbelievable 2,210lb ft of torque, 0-60mph in four seconds, 150mph top speed and a range of 200 miles. Performance that is, I think you must agree, quite literally electrifying. — Chris Rees

Delta E-4 Eco | 60,000+
Maximum speed: 116mph | 0-60mph: 6.5 seconds | Overall range: 140 miles
Power: 240+bhp | Torque: 1,106lb ft | CO2: dependent on recharging s
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