Is using auto start-stop bad?

Paradigm

A question...
Does stop-start actually reduce emissions?
Whatever the starting mechanism it will involve electricity from the battery & this will have to be replaced when the engine is running.
So extra work for the alternator = extra load on the engine = more fuel used.... or is that too simplistic?

neilmcl

forgotmyname wrote: »

Its bad if like the Fiesta that i spotted on Wednesday it was sitting there cranking over and not starting. Otherwise it will depend on your journey types.

If your journeys are so short that the battery may not be fully charging then disable it. If it gets a good run to recharge it and you also spend a bit of time sitting at the lights etc then leave it enabled.

If there's not enough charge then it will be disabled automatically anyway.

WellKnownSid

Paradigm wrote: »

A question...
Does stop-start actually reduce emissions?
Whatever the starting mechanism it will involve electricity from the battery & this will have to be replaced when the engine is running.
So extra work for the alternator = extra load on the engine = more fuel used.... or is that too simplistic?

Too simplistic. Remember when they used to tell you to keep fluorescent lights switched on because the act of switching them on destroys 16 rainforests?

peter_the_piper

fred246 wrote: »

Someone was asking me about getting Windows 10 - leave it till the end of the year when they've ironed out the bugs was my answer.

Don't leave too long or you'll have to pay.

peter_the_piper

Paradigm wrote: »

A question...
Does stop-start actually reduce emissions?
Whatever the starting mechanism it will involve electricity from the battery & this will have to be replaced when the engine is running.
So extra work for the alternator = extra load on the engine = more fuel used.... or is that too simplistic?

Isn't the battery always being recharged from the alternator anyway so its not really extra load.

nearlyrich

My current car has it and my last car did too, so just about 4 years, I have autos because that's what the company offer ( I like them anyway) and I keep the S/S on I am not sure it would be as simple in a car with gears..

neilmcl

nearlyrich wrote: »

My current car has it and my last car did too, so just about 4 years, I have autos because that's what the company offer ( I like them anyway) and I keep the S/S on I am not sure it would be as simple in a car with gears..

Why wouldn't it be. You come to a stop, put the car into neutral, SS comes on. Drop the clutch, select gear, engines starts again, simples.

In fact I've a work colleague who has an auto with SS and tells me it's a pain in the backside because it keeps coming on in every situation he comes to a standstill. So he now leaves it disabled.

ballyblack

Isn't the battery always being recharged from the alternator anyway so its not really extra load.

The alternator will work slightly harder in the few minutes after starting to recover the battery charge. This will take more power out of the engine via the alternator drive pulley(extra load)

Overall this effect will be negligible on fuel economy but its not 100% 'free' energy


.

molerat

On my car it is enabled by default and you have to switch it off every time you start the engine. It can sometimes be a pain as I have always been a put it in neutral type of driver.

Paradigm

WellKnownSid wrote: »

Too simplistic. Remember when they used to tell you to keep fluorescent lights switched on because the act of switching them on destroys 16 rainforests?

Remember when they taught physics at school... you don't get anything for nothing!
Energy is energy & it comes from somewhere...does stop/start save fuel & emissions or is it a gimmick?