Is Stop-Start system costly on the long run?

goldspanners

johnnyroper wrote: »

personally dont see the benefit of this system myself justa case of car makers being seen to do the right thing in terms of co2,i also think starter motor/ring gear wear will be increased along with increased stress on DMF in diesels.
as for engine position it stops while 1 piston is on the combustion stroke of cycle so it can start back up again without much turning of starter motor.

but just how does the engine manage to stop in this position and not its normal rest position. and if it does this would mean wear on the ring gear would be more spread out over the whole gear rather than just at 2 points.

johnnyroper

goldspanners wrote: »

but just how does the engine manage to stop in this position and not its normal rest position. and if it does this would mean wear on the ring gear would be more spread out over the whole gear rather than just at 2 points.

ecu gets info from crank sensor and then determines best position to stop the engine,quite how it is made to stop in a different place to normal rest position i do not know just going on what i was told by a mate who is still in trade and has more of an idea.

johnnyroper

Pew_Pew_Pew_Lasers! wrote: »

Some have stronger starter motors, and power the belt-driven devices (AC etc) from an electric motor instead.

I can't see that its a bad thing tbh, particularly in urban areas where there is normally lots of standing traffic. Lower emissions has to be a good thing.

surely any potential gains from stop/start technology would be wasted if driving the normal belt driven stuff by electric motor?it would take a fair amount of power to run a motor big enough to drive alternator,A/C ,power steering etc.

motorguy

harveybobbles wrote: »

...also what happens in winter if you have your heater on, heated seats, heated screen etc...? Will the extra load of firing all those up be false economy?

I personally can't see any benefit or point in the start/stop system...

I've it in the Passat bluemotion - basically the car decides if it is efficient to use stop/start. If certain funtions are being used - eg heated screen OR interior is below the temperature the air con is aiming for, then the car wont use stop start.

roddydogs

And the Road Tax is less, as less CO2.

motorguy

wazza wrote: »

Due to this the eco version shows improved fuel consumption and low emissions which means your road tax is free.

Not true. The eco versions of the Seat / Volkswagens etc use a whole raft of changes to improve economy / lower emissions.

I have a passat bluemotion which has the following :-

• revised ecu settings
• start / stop
• low resistence tyres
• lowered ride height for improved aerodynamics
• lowered tickover speed
• revised frontal aerodynamics
• revised gearing in 4th / 5th gears
• cruise control
• gear selector indicator
• lighter weight alloy wheels

On average i get 60mpg on fairly mixed driving - some motorway, some country roads, some town work. I'd estimate that to be 10-15mpg better than a 'regular' passat over the same routes.

The best i've got so far was on a run to work over 23 miles, mostly motorway and into city traffic - 90.1mpg!

motorguy

johnnyroper wrote: »

surely any potential gains from stop/start technology would be wasted if driving the normal belt driven stuff by electric motor?it would take a fair amount of power to run a motor big enough to drive alternator,A/C ,power steering etc.

I think thats the whole point though - there are a huge amount of engine revisions required to make this work.

motorguy

To be honest, i dont understand why for 'regular' cars - focus, golfs, passats, mondeos, fiestas, etc they dont just incorporate all this extra functionality into all the range and make it standard.

I know BMW have done this already, but it just seems odd that there is technology out there to make cars an easy 15% more economical without really impacting driving, yet its resigned to 'eco' versions?

movilogo

I read somewhere most stop-start systems are designed to operate over 150,000 times. That's more than normal lifetime of a car.

If you are worried, just switch it off.

Strider590

Gimmick IMO, the EU will take it on just as with other pointless and silly gimmicks.

The cars battery for this is a very expensive/large unit, I dread to think what it costs to replace.... But that cost is bound to out weigh the fuel saved in the first place.