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BMW i3 (2013) electric car test ride
25 February 2013 09:00
Onto the handling circuit
After a few high-speed laps, we turn off to explore the handling circuit. The 1.2mile loop contains the full works: fast corners, slow corners, gradients, surface variations. Novices who encounter BMW’s baby Ring for the first time next to a pro are bound to reach for the sickbag halfway through the course. The blue and white psychedelic i3 stops at the gate, waits for the striped bar to go up, silently drives through, then points its stubby nose towards the first bend.
All 184lb ft of maximum torque grabs the rear rubber at the word go, and again there is not even the faintest trace of wheelspin. ‘Just like the VW Beetle back in the old days,’ murmurs Kranz. ‘That’s what dynamic weight distribution will do for you.’ The i3 threads through the blind S as if it was guided by an invisible rail. A tight right-hand kink approaches rapidly, but the confident Kranz brakes so late and hard enough to cause whiplash. The car zooms towards the apex, kisses the cobbles and flies out onto the short straight. This is extraordinary.
The i3’s most awesome dynamic talent is its incredible grip. The made to measure tyres are about as narrow as those of a 125cc motorbike, yet they hang on almost as tenaciously as BMW’s latest DTM racer. ‘It’s not rocket science,’ says Kranz. ‘All that matters is the size of the contact patch.’ The 19-inch tyres may be skinny, but their tall height generates the same contact patch as a low-section 16-inch Mini tyre, says Kranz.
Although the snow keeps falling, it does not take long to establish a racing line which widens a fraction with every lap. Even at ten tenths, the i3 remains calm and composed. Try eleven tenths, and you’ll experience some understeer as the front wheels try to scrub off excessive energy. Go for twelve tenths and lift off in the middle of a tightening bend, and you will encounter a nudge of oversteer accompanied by that familiar faint ESP snarl. Since the handling is as neutral as a good referee, you can open up the steering quite early and put the power down accordingly. There is very little lean considering the considerable pace, and I don’t recollect more than a faint trace of front end pitch and no yaw at all. This i3 appears to handle like the best BMWs.
The i3’s steering is an unassisted rack-and-pinion device, but it’s by no means slow, heavy or indifferent. At 2.5 turns from lock to lock, it is unexpectedly quick, with a commendably tight turning circle. BMW quotes just under 10 metres, but in traffic the incredible manoeuvrability feels more like eight metres, which would equal a London black cab. Since the front wheels have no propulsion duties, the steering - devoid of wind-up, shock and fight - is commendably tactile and communicative. Watching Ulrich Kranz at the helm is a revelation. If his sparse and well-timed inputs are anything to go by, this BMW is every bit as entertaining to drive as any of its front-engined sister models. And what about its stability during an emergency lane change? Stupid question: the i3 zig-zags past an imaginary obstacle with such determination that the delicate measuring equipment in the boot bangs together in loud mechanical protest. ‘No problem at all,’ chuckles Herr Kranz: ‘This car learned to cope with every elk in our simulator early in its life.’
A punishing ride and refinement test
Next on the agenda is the torture track. That’s torture as in about twenty different attempts to upset a vehicle’s composure, to kick it off course, to push the suspension to the brink. We get thrown about in the cabin as the road starts to attack the i3’s aluminium chassis or ‘drive module’. But despite all sorts of irritations - lateral, vertical, horizontal, diabolical - the four-seater stays firmly planted. And while there is the odd groan (all well as noticeable windnoise) from the bolted on camouflage cladding, the body itself remains eerily quiet. No undue resonance, no rattle or scuttle shake, no protesting seals and joints, no suspension thump, only a distant tyre hum and that faint e-motor whir which actually sounds quite sporty under full acceleration.
The upper ‘life module’ is so stiff that, with doors closed, it resembles an oyster on wheels. Although the body connects to the drive module primarily via nuts and bolts, the tight fusion between the two clamshell elements ensures the i3 is quiet as a whisper. And it possesses a truly compliant, occasionally even cushy ride that a Mini or a 1-series can only dream about. Kranz says it’s due to generous wheel travel, and low unsprung weight. ‘The large wheels tend not to drop into potholes the way smaller-diameter rims do, and the tall sidewalls contribute a special suspension effect of their own,’ he adds.
Just before the sun sets, we go play on the skidpad. There are various radii and surfaces to choose from, and we try them all. The goose-pimple growing 60mph low-friction circle is ideal to simulate high-speed cornering at the limit. Like an M3, the i3 can be easily controlled by steering and throttle. When you give it stick, the typical attitude is a subdued four-wheel drift which becomes a little wavy as you begin to modulate the torque flow and the steering angle. And guess what: the ESP tell-tale does not light up once. On the smaller-diameter 45mph track covered with freshly fallen wet snow, it’s a different story altogether. Here you get enough momentary power oversteer to frighten the passengers, here stability control is indeed required to quash lift-off drama before it begins.
Speaking of lift-off, it is worth noting that you can step off the accelerator even in the middle of a fast corner. ‘Lift-off is essential in a car like this,’ reveals Ulrich Kranz. ‘After all, energy recuperation largely depends on it.’ In city traffic, the secret is to avoid touching the brakes: merely lifting off generates enough deceleration, and helps recharge the batteries. The i3 has three driving modes, including a hypermiling Eco Pro Plus, which caps the peak power output, restricts the maximum speed to 55mph, adjusts the transmission algorithm, recalibrates the accelerator action and reduces electric loads to a minimum. The other two drive programmes are Comfort and Eco Pro.
Time to wrap up the late afternoon session, time to head for the dry and warm garage for a closer inspection of the car. Unlike other BMW models, this one is made almost entirely in-house. The fully packaged battery stack, the 170bhp electric motor, the single-speed transmission and the performance electronics are manufactured by BMW. The same is true of the carbonfibre body (the raw material is shipped from Moses Lake, USA, to Wackersdorf, Bavaria) and the aluminium chassis assembled in Regensburg. Unusually, just 20% of the components (by value) come from outside suppliers. Among these items are the energy cells from mobile ‘phone giant Samsung, the Fuchs aluminium wheels and the special compound Bridgestone tyres. LED headlights and a Bang & Olufsen sound system are among the options.
The first ride verdict
The i3 is shaping up to be a breakthrough electric car. It delivers dynamic thrills like no electric car before it. The steering seems highly involving, the drivetrain’s punch would flatten a Leaf, and the handling and road-holding seem up there with BMW’s best. Ulrich Kranz and his team appear to have succeeded in bringing pure driving pleasure to the environmentally friendly car. We’ll know for sure when we drive the car in summer 2013.