23 July 2012 by Lem Bingley
electric Volkswagen Golf Blue-e-Motion
takes its cue from Nissan’s pioneering LEAF, but adds a fresh approach to regenerative braking; so how does the Volkswagen Golf Blue-e-Motion compare to the Nissan LEAF?
Volkswagen is gearing up to launch a battery-powered family hatchback, to compete with the Nissan LEAF. Named the Volkswagen Golf Blue-e-Motion, the new electric car should go on sale in early 2014 and will utilise the upcoming seventh-generation Golf bodyshell, which has been engineered with the option of an EV drivetrain in mind.
Prior to the new car’s arrival, VW has built a fleet of 80 prototypes based on today’s sixth-generation hatchback. We took one for a test drive to assess how well it performs against the LEAF, which has beaten it to market by three years.
From the outside, the only real clue to the Blue-e-Motion’s power source is the unobtrusive lack of an exhaust pipe (aside from the promotional stickers plastered over our car, of course). Even once under way, the electric Golf remains incognito because it synthesises the warbling engine note of a petrol-powered V6. The sound, intended as a pedestrian alert, even rises in pitch along with road speed to perfect the disguise. It falls silent at 35kph (about 22mph), when the tyres begin to drown it out in any case.
Not much of either sound makes it into the cabin unless you open a window. The electric Golf is supremely quiet and smooth from behind the wheel.
The Blue-e-Motion technical set-up is similar to the Nissan LEAF in some ways, and different in others. Both are front-wheel drive, and both use an air-cooled battery, for lightness, simplicity and cost reasons. Both use lithium-ion chemistry. But while the LEAF’s battery is made up of 192 flat laminate cells, arranged into 48 modules of four, the Golf employs 180 cylindrical cells arranged in 30 modules of 6 cells each.
The Golf boasts a slightly higher rated capacity at 26.5kWh versus the LEAF’s 24kWh, although the quoted driving range is slightly lower at 93 miles versus the Leaf’s 109, probably because the Golf’s motor is a mite more powerful at 85kW (114bhp) compared with 80kW (107bhp). The Golf will scrabble to 62mph in 11.8 seconds, the LEAF takes a tenth longer.
VW’s engineers have packaged all the required electrical hardware, battery aside, under the Golf’s bonnet, whereas Nissan’s designers placed the LEAF’s charger in a noticeable hump over the rear axle, allowing a lower nose and better weight distribution at the expense of some practicality.
On the road, the Golf feels very much akin to the LEAF but is a little more involving – the LEAF sits the driver higher and has much lighter steering and brakes, for example. Like the LEAF, the Blue-e-Motion feels highly refined, relaxing and surprisingly eager to accelerate from moderate speeds when given full throttle.
The Blue-e-Motion is not simply a me-too design, of course. One notable area of innovation is in the driver’s ability to select the level of energy recuperation, also known as regenerative braking, while on the move.
By default, with the automatic-style transmission selector set in D, the electric Golf barely slows down as the driver lifts off of the accelerator. This “sailing” mode is designed to preserve a car’s momentum on fast, flowing roads, although one of the Golf’s engineers explained that the motor does have a slight braking effect even in this mode. As long as the motor remains connected to the wheels it must either provide propulsion or braking – it cannot simply spin freely. In practice, the level of braking is so slight (at less than one Nm) that it feels as if it would barely ripple the skin of a rice pudding.
The driver can activate a much higher level of recuperation by pulling the transmission lever back into a “B” setting. In this mode, the level of retardation feels like moderate braking, and indeed the brake lights are activated whenever the throttle is released in this mode.
The driver can also select three intermediate levels of regeneration, by leaving the transmission in D and using paddles attached to either side of the steering wheel. Repeatedly pulling the left paddle, marked with a minus sign, steps through the three levels of increased braking effect. Pulling the paddle on the opposite side reverses the sequence, while a small symbol on the dashboard displays which mode is currently in operation.
The driver is thus able to control how much energy is captured during deceleration from moment to moment, which should prove useful for maximising range and adjusting for the differing conditions when driving in urban congestion, on A-roads or on motorways.
The level of energy fed back into the battery is shown by a large analogue dial in the instrument cluster, which also swings around to show the level of power dissipation during acceleration. A blue sector is marked on the dial for more economical driving, while inset is a smaller dial showing the current range prediction. A second large dial shows road speed, with its own minor gauge displaying the battery’s state of charge.
In common with the LEAF, the Golf Blue-e-Motion uses a centre-console screen to provide supplementary information about the car’s performance, including a detailed animation showing energy flows between the battery and the motor.
Physically, the battery is packaged in a T-shape, filling the centre tunnel, the space under the rear bench and part of the boot. About 240 litres of an ordinary Golf’s 350-litre boot remains for carrying luggage, above a noticeably raised floor. A compartment is also provided for carrying the car’s charging cable.
A full refill will take about eight hours from a domestic 240V AC supply. VW is also working with other German manufacturers on a standard for high-voltage DC fast charging.
For the moment the prototype Golf boasts the unusual feature of twin charging ports – one under a conventional filler flap on the right rear haunch, the other hiding behind the VW roundel in the car’s nose. The intention is to keep only the front socket for the upcoming production model, although some work remains to be done to avoid problems with icing in cold weather. The Leaf’s nose-mounted charging socket, for example, is sheltered by both a close-fitting waterproof cap as well as a much larger protective flap.
Prices and sales arrangements remain to be decided. Nissan simply sells the LEAF as it would any other car, but Renault has pioneered a battery leasing scheme that lowers the initial entry point of EV ownership while raising ongoing costs. It remains to be seen whether Volkswagen will take its lead from either of these two models, or if it might dream up a third way all of its own.
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