Start stop BMWStart/stop technology is a bit like broccoli; we know it’s good for us but we avoid it if we can.

It makes perfect sense when you think about it. It’s an electronic widget that automatically stops the motor when the car comes to a halt, such as at a red light, and re-starts it when you lift your foot from the brake, usually just in time for your foot to start pressing the accelerator. The logic is that an idling motor at a red light is burning fuel for no result at all and it makes sense to turn the motor off. I know one woman who averages 15 minutes being stationary in her 65-minute commute twice every week day.

And yet I don’t know a single person who has driven a start/stop car and likes it. They complain about the light shudder that runs through the car as the starter motor cranks, they don’t like the slight delay in take-off, they say it’s intrusive. Some worry the starter motor will wear out faster, but start/stop cars have heavy-duty starter motors designed for it, as well as more robust batteries and engine mounts. This tech is also clever. If your air conditioning is running the motor will start up when the compressor needs to kick in, even if your foot is still on the brake. In some cars the motor will also start if your tug on the steering wheel so the power steering works.

For all of this, lots of drivers disable the feature by pressing a dash button (it has a little A enclosed by a circular arrow), but there’s a catch. Every time the ignition is activated the start/stop defaults to ‘on’, meaning you have to press the disable button every time you start a journey.

Start stop Subaru bIf you think start/stop is a crook idea there’s bad news; you’ll have to get over it. It has been brought about by tough emission laws in Europe that are bound to become universal. Right now it turns up in cars from Europe, or in cars from other countries sold into Europe as well as here, and it’s only going to get far more common. Car makers are doing everything they can to burn the least possible amount of fuel, thus reducing emissions.

So how much fuel does start/stop actually save? Some start/stop Subarus display a running tally of the fuel being saved, measured in millilitres, and it’s nice to see those millilitres steadily gathering as you sit at interminable red lights. But then it dawns on you that there are 1000 millilitres in a litre and even with long commutes it can take weeks to reach 1000. If you use the car a lot in traffic and save three litres a month that’s 36 litres a year, or about $40. If you don’t, well maybe the fuel you save would fill the mower.

America is the second-biggest car market in the world, big enough that manufacturers build cars specified for it, so while many Mazdas in Europe and Australia have start/stop, in the USA where emission laws are easier the feature is not included.

Tim Barnes, director of product planning for Mazda in the United States, told the New York Times that: “Our primary research says almost to a person, people turn off their stop/start systems.”

That’s one of the reasons that Mazda has no plans to introduce the technology in the USA.

So I asked Mazda in Australia what their experience is here. “We don’t have any official customer feedback on whether customers use it or disable it,” Karla Leach, senior manager of public relations said.

Published February 2017


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