start stop cars, do they work?

[telecat]

I found it annoying on a BMW 118d we had as a loan. It seemed to affect the car so that when cold the thing would stall more often. It also depends on how you drive. If you are in a jam that is moving every couple of seconds it becomes annoying. On the BMW it only did it if you were sat with the car out of gear and clutch up. Sort of a very moot point as to how pointless it was. It does however at least mean you can get a lower tax bracket and still switch it off.

[DavidHM]

Found it pointless on an Octavia Greenline rental I had. It took so long to kick in at traffic lights that it was basically time to go once it kicked in ... doesn't help that I tend to drive in traffic with the clutch in rather than the car in neutral. Seriously doubt it gave more than 1 out of the 68mpg I had overall from that car.

[SuperHangOn]

How long does it take at a standstill for the engine to cut out?

[sawman]

Interesting feedback guys, you have saved me an hour or so internet trawling for info. Sounds like a victory of marketing over utility

[NHK244V]

I've had stop start on all my cars (called the ign key) even my 1971 cortina had it, i get 47MPG out of my 1989 sierra TD with it round town, amazing technology great, brilliant, wonderfull.

[Bill Carr]

SuperHangOn said:

How long does it take at a standstill for the engine to cut out?

On the Fiat it's at the moment you pop it in to neutral. It only does this if you've travelled (forwards) above 5mph IIRC - it doesn't cut out if you've just reversed. Also, if there's a high electrical load the system won't kick in, so if you've got the stereo, air con, wipers, lights on, it won't cut the engine when you come to a halt. Similarly, if start-stop is engaged and you increase the electrical load, the engine will fire back up again to prevent the battery draining.

[Pferdestarke]

I disable mine as I find it too invasive. You also feel like a cheapskate at the lights when it cuts out and re-starts to the amusement of fatso in his mobility scenic with a knob on the steering wheel.

[XitUp]

Ozzie Osmond said:

If you are always driving in town stop/start could make sense, although if you're that worried about economy an electric or hybrid is probably a better solution.

Out on the open road stop/start is clearly irrelevant.

If you have genuine mixed driving then go for it - but don't pay too much for the privilege!

This.

We were next to a diesel merc at the lights the other day that had it, engine seemed to start very quickly, sounded terrible though. How does it work on an auto? Do you have to put it in neutral?

[cptsideways]

Its only real benefit is a reduction in emissions tax & consider it just that. I've seen some calculations where the average motorist would only be saving about 15L of fuel per year.

The BMW system seems to be the most annoying & random as to when it will be working or not.