Auto Design

By Giancarlo Perini. ©

We have driven, in a real environment, one of the some 1100 BMW ActiveE, that the German premium car maker will deliver as of December. This is the all-electric, plug-in, two-door, four-sweater, real-wheel drive sport car built from the first generation BMW 1 series coupé platform.  Handling, acceleration, speed and comfort are on a pair, or better, than the BMW120i Coupé and our feeling was that, indeed, we could go on for all the 140 km range promised by the lithium-ion batteries charged at 92% at start point.

Is it really the premium car of the future? It could, but BMW is working at something much better and is very confident that car buyers in the Megacities will love it. We agree, if the selling price is equivalent to a new generation BMW 3 series.

Driving, the ActiveE is a privilege reserved to a fleet of some 1100 drivers selected to contribute to the fine-tuning of the whole project “I”. They will help sorting out all potential problems through the next two years, in three continents.

“The BMW ActiveE is the BMW Group’s next systematic step towards an emission-free, mass-produced electric vehicle. After field tests in the USA and Europe involving more than 600 MINI E cars in the USA, Europe and China, the ActiveE fleet, will provide further valuable insights into the everyday use of the vehicle”, said one member of the team.

How serious this “pre-mass-production” EV is, is simply said: it combines the best of two real cars: the reality of the present and the near future. It shares the drive-train, the batteries, the electronic energy management and all related technology of the new “BMW i3”, although in a different and much heavier package of a reinforce BMW 1 series coupé.

For layout and weight distribution reasons the one-piece flat unit of the i3 is split here in three blocks. The drive train – i.e. the electric motor with gear and power electronics – sits directly on the rear axle.

This eventually reduces the space available in the trunk but the cabin is as roomy as a regular Coupé. The most notable differences from outside, apart the distinctive graphic work, is the addition of a scoop on the front bonnet (hosting a pack of batteries) and the absence of exhaust pipes at rear. The luggage compartment is standard, but the volume available is limited to 200 litres because the trunk houses part of the “power electronics” pack.

One of the three energy storage units takes up around half of the construction space normally occupied by the combustion engine and extensive measures implemented in this area guarantee optimal passenger safety in the event of a crash and also ensure that the high-voltage storage unit, ancillary components and battery fluid containers are not damaged in a collision.

Inside, the large and easy to read instrument cluster make sure that the driver has under control the way to its destination.

The instrument cluster and the control system iDrive are adapted to the electric drive concept of the BMW ActiveE and enhanced by specific display functions. Instead of indicating the engine speed, the instrument on the right of the cluster shows the amount of energy being taken from the battery or the current amount being supplied to it through recuperation. When the vehicle is at a standstill, the middle position of the needle indicates that the silent vehicle is ready to drive. If the vehicle is not ready to drive, the needle rests at the bottom left of the instrument. The “fuel gauge” below it indicates the battery charge level. Furthermore, the onboard computer provides additional vital information such as the remaining vehicle range, whether the air conditioning or the heating system is working.

In addition, a dedicated menu provides information on the battery energy level as well as remaining range. During charging it indicates the remaining charging time.

If the driver wishes to increase the range he can do that with the ECO PRO Mode. A simple switch changes the drive configuration and comfort functions to deliver a more efficient driving style. Less power is demanded with the same pedal travel and the air conditioning systems are set to use less energy.

By the end of 2013, when the car is in the garage and being recharged, car and driver can be connected and under control through a smartphone. This will be instrumental in remotely set the car to be ready at the right time, properly warmed up in winter, or cooled down in summer. Or to flash its lights or to horn when he or she can’t remember where the car was parked at the airport.

A look to the technical specifications of the ActiveE and some consideration about what can be expected of the “BMW i3” is very, very promising.

Now the 3 packs of cells weights 450 kg. This will not change much with the “i3”. They store 32 kWh of energy and ensure a range of at least 160 km (some 100 miles) according to BMW. However, the company says that “according to the American consumption cycle FTP72, the vehicle has a range of up to 240 kilometres (150 miles) independently of external climatic conditions.”

This is realistic with a lively but sensible driving style, when energy consumption should range around 0.12 kWh per km. The permanent-magnet hybrid synchronous motor grants up to 125 kW of power and a constant torque of 250 Nm. Acceleration to 100 kph requires 9 seconds and this is more than what you need in city traffic and beyond. The top speed is limited to 145 kph when the motor revs are cut at 12.000 rpm. Obviously, CO2 (from the car) is 0 g/km.

Recharging the battery from a conventional power socket at home takes 16 to 20 hours. Too much for a full charge at night (from 18:00 to 7:00 there are only 13 hours) but at 240 V/32 A (good for 7.7 kWh) a full charge takes 4 to 5 hours. BMW proposes its so-called wall box, a 32-ampere power supply terminal, installed at the user’s home and optimised to obtain the shortest possible charging times.

How different it is to drive the ActiveE from a combustion engine BMW? Not much. At first, under heavy rain, you wonder if you are absolutely isolated. The answer is obvious, but you cannot fight your instinct. You also question how much energy the wipers absorb and how they affect your range. Than the first surprise is the strong deceleration of the car as soon as you lift your foot from the accelerator. The car brakes by itself, recovering energy and in most instances (BMW estimates them at 75%) you do not even need to touch the brake pedal.

Next you wonder if the following drivers are informed of your deceleration. Yes, they are the brakes lights go on even if you do not brake. There is no sound at all? Not true. There is a low and gentle sound that tells you the engine (at the rear) is running quietly and smoothly. Yes, there is no vibration from that department, or from any other parts of the car. The tyres are comfortable and communicative. And so is the electric steering wheel. They are not yet specific for EVs and are 205/55R16 with running flat properties and optimised for rolling resistance.

The power is quite reasonable on this car but the weight is not.  Without any passenger the scale shows 1815 kg. This is as much as 515 kg more than a BMW 120i Coupé with the same tyres. Now let’s consider that because of its all-new architecture, materials and construction technology the 2014 BMW i3 will be “some 600 kg lighter” (according to a BMW official) and there you go with a set of preliminary, very promising, figures.

In the next two years, before the launch of the ultimate car of the future, the ActiveE will gather all sort of experience on the road in the hand of typical American, Chinese and European drivers.

In the meantime, at the Leipzig factory, BMW will experiment and test the entirely new and very innovative material manufacturing and production process. A new way of designing and building cars that is even more intriguing than the cars itself.