how much fuel used in idle mode

mutley74

Richard53 wrote: »

So the one time the system is potentially of benefit is the time you disable it?

no...that will depend on traffic conditions etc...if I am in slow moving traffic and I can see that the car will be moving/stopping constantly every few seconds, it will be probably best to disable.

I will give it a go by disabling when car is stationary to see if it lets the car switch back on to normal mode. Guess like most things it takes practise and experience.

Ultrasonic

mutley74 wrote: »

guess in such situation (traffic) probably best to disable the s/s system

That's pretty much exactly what start-stop is designed for though! Or at least the situation where it was introduced to improve fuel economy.

I should say I've not spent any time looking into the reliability of such systems, I'm just being cautious/cynical .

But in your case you'll be using it comparitively little so why not do so? They can't be that fragile or city drivers would be having problems with them all the time...

Richard53

We had a brand new Mini One loaned to us at work and I drove it quite a bit. On our site, used as general short trip transport, it's stop-start every few hundred yards, and a fair replication of city traffic. The system worked faultlessly and the starting was pretty much instant. By the time you had the clutch fully depressed, the engine was up and running. It was a new car, of course, and that is to be expected, but it did make me wonder if it would be just as instant and hassle-free after 5-6 years or 50k miles.

I got used to driving it, but I did make a mental note never to buy a car which had this feature. Not only is it the usual complaint about modern cars, 'something else to go wrong', but also that if it did go wrong it would be likely to disable the car. Perhaps I have trust issues.

mutley74

Ultrasonic wrote: »

That's pretty much exactly what start-stop is designed for though! Or at least the situation where it was introduced to improve fuel economy.

I should say I've not spent any time looking into the reliability of such systems, I'm just being cautious/cynical .

But in your case you'll be using it comparitively little so why not do so? They can't be that fragile or city drivers would be having problems with them all the time...

I agree I will question the reliability too, but plan to sell the car within 2 years and its in warranty.

A._Badger

mutley74 wrote: »

I agree I will question the reliability too, but plan to sell the car within 2 years and its in warranty.

And that's really all the car makers care about - whether it A/ shuts up the rule-setting bureaucrats in the EU, B/ satisfies fleet buyers and B/ lasts through the warranty period.

Like a lot of modern wonders this is going to prove very interesting when these cars are starting to be third and fourth hand.

LandyAndy

Ultrasonic wrote: »

OK, but to suggest idle fuel consumption is so low you could only detect it with specialist lab equipment is overstating it. We've also been talking about diesel idle figures, the effect will be bigger for petrol cars.

Years ago on my 1985 Vauxhall Senator 3.0i the trip computer showed consumption as 0.4 gallons per hour at idle. I always thought that was a surprisingly small value.

almillar

Don't forget that we've all got MANUAL stop/start systems - as long as your car is in good condition and you don't do short journeys all the time, I consider it fine to switch the engine off if you know you're going to be stopped for a long time - that's even 60 seconds plus.
I've got a Mini Cooper S with stop/start, and it still surprises me with when it thinks it's OK to switch off - a few hundred yards after starting my journey, when the engine can't possibly be up to temp, but it's also reluctant to do so when air temp is below, say around 11 degrees centigrade (and no big electrical loads).