Do 'stop start' cars save money?

peter12345678910

A little hassle changing the starter. First RAC booked me a garage that do reconditioned starters. Then he gave me a push. Then I stopped at a busy roundabout, car behind me gave me a push. Then it stopped again, told a couple of strangers to give me a push, then I got to the garage.

Though according to Scotty on YT it is bad for engines. I see it is a gimmick also start stop batteries are more expensive.

WellKnownSid

The other saving is, of course, on CO2 emissions.  Rightly or wrongly, we've owned or leased a series of cars on £0 - £30 annual road fund licence thanks to stop/start.  That's another saving of at least £100 a year per car - probably well over £2,000 saved since 2013.

The major component manufacturers (Bosch, Valeo, etc) launched their next generation stop/start systems back in around 2010 I think - I know lots of people still believe they are the work of the devil, but it's progress.

If we didn't have progress we would all still be riding around in cars with these, and I remember the uproar and problems when car manufacturers first tried to remove them!

sevenhills

WellKnownSid said:

If we didn't have progress we would all still be riding around in cars with these, and I remember the uproar and problems when car manufacturers first tried to remove them!

When AI knows how long you are going to be stationary, stop-start may work.

J63320

I have ‘stop start’ on my VW T- Cross, and I doubt if it saves much fuel, if any. For one thing, the engine sometimes stops immediately, and if I’m only pausing on a quiet road to check for traffic before turning, it has to start again right away - this must surely use more fuel that if it just kept running for those few seconds.
Also, if it stops when I’m in a queue of slow moving traffic, it “decides” that I need to move when the car in front does, so it starts again; in fact I can’t see the point of creeping along, and prefer to let a gap open up before I move. If it would let me decide how to drive my own car then I would save more.

Rodders53

I thought that stop-start was all about emissions reduction when vehicles are stationary, rather than fuel savings or economy?

sevenhills

Rodders53 said:

I thought that stop-start was all about emissions reduction when vehicles are stationary, rather than fuel savings or economy?

But I believe that every time you start your engine, more fuel is pumped in, in order to start it.

WellKnownSid

sevenhills said:

But I believe that every time you start your engine, more fuel is pumped in, in order to start it.

Given that billions have been given away in Government tax incentives to buy these cars all over the world, I think you know deep down that cannot be true.

Of course, when it comes to cars faking NOx emissions in tests, that's a whole different story, but these days cars don't sit there cranking for 35 seconds every time they start at the lights.

It's the same as the old wives' tale of 'don't turn off fluorescent lights because they use the equivalent of two power stations when you turn them on'.

sevenhills

WellKnownSid said:

Given that billions have been given away in Government tax incentives to buy these cars all over the world, I think you know deep down that cannot be true.

Of course, when it comes to cars faking NOx emissions in tests, that's a whole different story, but these days cars don't sit there cranking for 35 seconds every time they start at the lights.

If the auto-stop isn't turning the engine off, I assume that is because the battery is low. Although I haven't had any issues recently. So the engine needs to continue to charge the battery.

About two months ago, first thing on a morning, the van told me that the battery was low, but that is the only time.

motorguy

sevenhills said:

I drive a VW Crafter that has stop-start techknowledgy. Sometimes the icon comes up on the dashboard and it just carries on ticking over. Sometimes it switches off when I am not expecting it, because I often turn it off.

Sometimes it tells me to start the engine with the key, it's just a pain.

I cannot believe it saves any money, when you take into account it may need a new start motor earlier.

I sometimes switch the engine off with the key, when I am sure I will be stood for a while.

Is that legal, is it ok to sit at the traffic lights with the ignition off, waiting to start the engine. Will the glow plugs or coil overheat?

I thought the point of it was to reduce emissions, not to save the driver money.

Tens of thousands of cars sitting ticking over at traffic lights in cities cant really be a good thing.

oldagetraveller1

Never had it but suspect it's just a gimmick.

Would the amount of fuel allegedly saved be equivalent to the cost of a new overworked starter motor when it prematurely fails?

In my opinion, it should be off by default and the driver chooses whether to use it or not. Rather than on by default and, if possible, turned off after starting driving.