Monday, May 28, 2012

Auto stop start

I recently rented a car that had one of those auto stop-start systems on it for fuel efficiency. The idea is that when you're stopped, the engine turns off and then as you get ready to move off, the engine starts again. The car I was driving was a manual so the system keyed off the clutch pedal. When I was stopped, if the car was in neutral and I took my foot off the clutch, the engine stopped. The first time this happened I panicked and put my foot on the clutch and turned the key to re-start the engine as I assumed it had stalled. Of course as soon as I pushed the clutch down, the engine started itself so by the time I turned the key, I got that awful "you're killing your engine" noise you get when the starter tries to engage with a running engine. That noise made me take my foot off the clutch again so then the engine stopped again. It took me one complete green cycle of the traffic lights, parked with the hazard lights on, trying to figure out just what the hell was going on. In the end I found the "off" button to turn the stupid function off completely but in this particular car it reset to "on" every time the car was parked. If you're a regular reader you'll know I despise in-car gadgets like this and auto stop-start has shot right into the top three of my most hated functions now, right next to auto lights and auto wipers. It's a pointless system that wastes more petrol than it saves (according to Auto Express and Motor Trend at least), and certainly induces far more stress on the engine's starter than it needs to. The additional complexity in wiring, sensors and ECU coding seems illogical and unnecessary too and it strikes me that on cars fitted with this system, we can probably guess with 100% accuracy what the first thing will be to fail. Either the stop start function, or the starter motor itself. Fortunately this particular car was a VW Golf and because of the ready availability of products like the VAGCOM (which I already own for my Tiguan) it would be child's play to turn this function off for good.