BMW's i3 electric car
Well, the thing an EV relies upon so heavily is also the thing that's essential to good driving - momentum. Makers of EVs are constantly battling to extend the range of their vehicles and only part of that process is improving battery technology. The other part is ensuring that not a single kW is wasted when driving. Energy lost in braking and coasting is recaptured and used to generate more battery charge. But EV makers are also encouraging drivers not to waste that energy in the first place, by conserving momentum.
Conserving momentum does not mean driving slowly. It means being aware of the capabilities of your own vehicle, reading traffic with an analytical eye and having complete confidence in the route you have chosen. Conserving momentum means being a great driver and probably a quick one, too.
If you can drive from home to work in the traffic flow and touch the brakes only when you actually need to stop, you have mastered momentum. Probably not possible in an absolute sense - but it illustrates the point.
If you're familiar with the energy flow meter on a Toyota Prius hybrid, you'll know what I'm talking about. That was probably the first piece of in-car interface that really aimed to educate drivers about the merits of conserving energy. Unless you count the vacuum gauge on your dad's VC Commodore Four.
EVs take this concept a step further. The Holden Volt was the first car capable of pure-electric driving to launch in New Zealand. On its dashboard, the Volt has a vertical bar-type graphic with a large green ball in the centre. If you are driving smoothly and using the vehicle's momentum in the correct way, the ball will stay green, large and in the centre of the graphic. Accelerate too hard and it bounces up to the top, becoming small and going a worrying orange hue. Brake and the same thing happens towards the lower part of the graph.
Mitsubishi Outlander PHEV
That's a good lesson. We all understand that accelerating too hard is wasteful. But the flipside is that every time you touch the brakes, it's an indication that energy has been wasted because you're going too fast.
There are different principles in play if you're driving right to the limit, of course, because you might be using your brakes to transfer weight around the car to generate more grip and/or traction. But for those of us without a motorsport licence, to drive a car briskly over a difficult piece of road with minimal braking, by reading the terrain and traffic ahead, is really something to strive for. An EV will help you do that.
So the Volt encourages you to conserve momentum. More recent EV offerings have actually progressed towards giving you the tools to do so more effectively. The Mitsubishi Outlander PHEV has a couple of levers on the steering column that look like gearchange paddles, but they're not. You use them to increase the amount of power regeneration (and therefore drag) for the electric powertrain, through several stages.
Naturally, you do this when decelerating to a stop or going downhill, instead of leaning on the brakes. It's the EV equivalent of engine braking and it's a wonderful thing, not only for recharging the batteries, but for teaching the driver about anticipation and stopping distances. See what I mean about breaking (braking) old habits?
In an age of automatic transmissions, we've become a very stop-start automotive society. Press one pedal hard to go, press another hard to stop and never really think about what happens in the middle.
Indeed, many driving instructors actively discourage us from the practice of engine braking. To quote one of mine from a few years back: "Brakes are cheap to replace but engines are not." True. But no longer relevant for EVs, which must surely help bring back the lost art of engine braking, for want of a better term.
Holden Volt
Actually, there is a better term. I attended the international launch of the BMW i3 last year and it was there I heard the phrase "one pedal driving" for the first time. The i3 powertrain has a lot of regenerative drag in city driving, to the point where there's really no such thing as coasting.
The idea is to time your deceleration perfectly so that the car stops of its own accord at traffic lights and intersections without you braking at all.
Hence one-pedal driving. It takes a couple of days to master, but it works brilliantly and it's a whole new way of thinking about driving. A better way, I would argue.
So, I'll meet you in town in 2020. First one to brake pays for coffee.
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