Turning engine off at traffic lights...

[jont]

If, like me, you never buy a new car, the extra technology cost is unlikely to influence you much. I kind of agree with you about the total cost of manufacture of the vehicle in CO2 terms, but fuel costs are where it speaks to the motorist - in the wallet. I doubt, personally, if the stop start systems are all going to blow up at exactly 3 years old - there are plenty of cars with the technology which are already over that.

I'd rather pay a couple of quid on every fill up than have an extra £00 bill every year or two.

[Mr Cholmondeley-Warner]

I think you're scaremongering ...

... and anyway, a couple of quid every fill up will save you more than enough.

[jont]

I think you're scaremongering ...

Nope. Still bitter about our Skoda. And that hasn't even got stop start

[TheInsanity1234]

Let's say your car averages 50mpg (should be somewhere in the right ball park) so "an extra mile or so per gallon" equates to somewhere between 0 and 4 percent saving. That's roughly the equivalent of having a Tesco (or name your favourite supermarket) 2p off a litre voucher every time you fill up. Not worth having?

We fill up with approximately 55 litres from empty, so with a 2p/l off, that would be £1.10 per tankful, and we, on average, fill up every 2 weeks, so that's £28.60 per year saving on our fuel bills.

Hmm.

When you start driving the car, who's going to be paying for the diesel?

Whoever is unfortunate enough to have to fill it up from empty, I guess?

[Improving driver]

I had stop/start on a Volkswagen Polo Classic CL Formel E which I bought in 1982. 10 years later the stop/start was still working fine. My current car, another VW, has been free from problems on its stop/start for over 3 years from new. Reliability seems to be OK.

[Kimosabe]

The subject probably says it all really.

When at traffic lights and local knowledge tells you it's going to be a long wait, is it sensible to turn your engine off? I'm talking about a non stop-start vehicle.

I've started doing this I recently but am not sure whether it's beneficial or advisable.

Your thoughts?

I would say it's a bad idea to disable your car by turning off the ignition when stationary at lights. I think there are times when it's reasonable to do so, such as when at some level crossings or possibly in gridlocked traffic but lights are a hazard/ controlled junction. Without needlessly exploring either the array of differently controlled lights or the depths of the 'what if' Random Possibility Generator of Catastrophic Possible Eventualities... what if you had to move your car to allow, say, an emergency vehicle to squeeze past or a filtering motorcylist and couldn't because the car wouldn't start. Also some cars still overheat if not left running to allow the systems to cool everything down. Can't say it's ever happened to me, though I always thought it would in our ex Fiat Panda of many colours.

I also think savings for fuel efficiency can often be a bit of a white elephant when weighed against how much extra effort everything would have to go through if the number of on/offs in a car not fitted with Stop/Start gizmology escalated to dozens of times every day. As cars become more efficient, fuel prices rise and if this is more about pollution, take a trip to any town or city in eg.India to see what little effect our effort have when faced with the pollution Indian traffic generates.

PS: As a slight personal aside, I remember when many of the buildings around Whitehall were thoroughly stained black with decades of industrial and traffic pollution and just how long it took to have it all cleaned, so that wasn't a dig at India.