Speed Limits and EV’s


Following on from my last entry where I discussed going reasonably slowly, i.e. sticking to the speed limits, I suggested that “the car maketh the driver”. This principle has held true for the 23 cars (and 3 bikes) I have owned and for a great many more people who I have known as well. The idea is that despite perhaps our belief or intuition, that it is our own temperament and experience that determines how we drive, I contend that this is heavily modified by what we sit behind the wheel of.

For example a considerate driver of a Honda Jazz is likely to put their foot down and be a little (or a lot) less considerate in a Porsche 911 Turbo. Never has this been more clear to me than in my Nissan Leaf EV, but in reverse.

In this car everything is designed to psychologically encourage low energy driving. The amount of miles remaining takes centre-stage on the dash, a game where you grow trees depending on how much energy you save as you drive is on the dash for all to see (in fact your statistics are uploaded and compared with other Leaf/ENV2000 drivers around the world) and the car’s cruise control can be activated from 23 mph and is often used, as it accelerates and manages your speed much more smoothly and therefore saves more energy than manual throttle control.

As such I am more likely to drive at the speed limits than in any other car I have ever owned. Precisely at the speed limits by using the cruise control. I do account for the speedometer 10% inaccuracy by setting my cruise control at 33 mph in a 30 zone for example, so my actual speed is 30mph. In every other car I have ever driven I have either been fairly indifferent to the speed limits, often in cars/on bikes which can easily and quickly exceed it or have been driving slower vehicles where it is an effort to get up to speed and therefore quite an achievement to exceed the speed limits.

Over the years I have been flashed by many cameras, but never received a ticket and I have never been on the famed “speed awareness course”. Perhaps I should go, or perhaps I should continue to drive the Leaf which actively and cleverly encourages the saving of energy by psychologically inspiring careful driving.

It is odd that it works this way, because I should drive the Leaf like a boy racer (I’ve got the alloys!) It is fast, it accelerates rapidly and has a totally flat torque curve, the cost of running it is very low, so you can go fast cheaply, and the wear and tear on the mechanical/electrical parts is very low even if you have a heavy left foot. But oddly I don’t, the game isn’t to get there as quickly as possible, but to get there with as many miles of range still available as possible, a totally different sport.

What about the effect on other drivers. Well it seems that two things predominate. The effect of actually going at the speed limit and the effect of using cruise control.

When you actually drive at the speed limit it is more often the case (I’d say around 50% of the time during peak periods) that someone will end up driving up your ar*e. Its a running joke that they will always be driving an Audi or BMW but in all seriousness, confirmation bias means you notice this quite a lot. In almost every other car I’d just go at the speed everyone else is going but in the Leaf I feel more inclined to dig my heels in and make a statement that the speed limit is enough. In fact during my drive to work if I am overtaken by someone, I nearly always come to stop just behind them at the next set of lights, their overtaking manoeuvre got them nowhere. The Leaf discourages harsh breaking and accelerating, and whilst on a racetrack there are only two acceptable states of change of speed i.e. accelerating or breaking (no cruising) if you want to set a fast lap time, on the urban/suburban or even busier country roads, gunning it only results in having to break hard at the next junction and is a total waste of fuel and brake pads.

Cruise control is another area where problems arise. Those using it are constantly frustrated by the changing speed of other road users. When on cruise, which in the Leaf is particularly useful, you are always having to nudge it up or down. Driving without cruise we tend to speed up going downhill and slow down going uphill its a natural thing to do. This means cruise control driving and manual throttling are always going to be odd with one another. This has led some manufacturers to fit adaptive cruise systems that use radar or other sensing technologies to keep you a set distance from the car in front, even auto braking if they slam on the anchors.

Whether this gentle driving effect of regular EV’s also extends to high performance EV’s such as the Tesla Model S I am unable to say until I get my Model S (Tesla if you’re reading I am still waiting). But I suspect it might be a little more tempting to go fast, given the higher performance and the considerably greater range.


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