Porsche Start/Stop Technology

[RickZ]

I was talking to a Porsche salesman the other day who sounded quite knowledgable on car engine technology having built a few cars for track use. We discussed Porsche start/stop technology and the wear and tear this technology causes to starter motor and battery. He informed me Porsche start/stop doesn't use the starter motor, allegedly the engine stops with one cylinder at top dead centre then re ignition restarts the engine. I understood this process was used in conjunction with the starter motor to reduce wear and tear. Does anybody know for sure how Porsche start/stop technology work....

[Paul]

Happy to be corrected, but I can’t see how the engine can restart without some sort of rotational input from the starter motor...(whether single or double solenoid)

[RickZ]

The guy who informed me suggested rotation is the result of ignition in the TDC cylinder moving the piston. I asked him why use starters at all if this works he thought this process only works with a warm engine. I still think he got it wrong and this process works in conjunction with the starter....

[bennachie]

The just past TDC and firing to get 'instant' start is correct. There was a big presentation about this aspect at PEC when I was there a few years back. Cant remember anything about starters but would have thought it was needed to give a 'tiny spin'. The key point was stopping the engine at a cylinder 'firing point' to ensure instant starting.

[Guy]

So how does this work in diesels?

[RickZ]

Good question. I guess on diesels the starter is required for compression ignition so maybe Porsche use one system for diesels and the other for petrol engines...

[happy days]

I smell something very much like bullshit on this one. On both my cars (diesel Macan and petrol 718) I can hear the starter operating when it's time to get going again.

[Col Lamb]

The Porsche Stop Start tech is junk.

The absolute best feature is the inhibit switch that stops the damn system from working.

Or you can just put the car in Sport mode and that also inhibits the system.

I got totally fed up of slowing down at a Stop junction only got the damn stupid system to then stop the engine just as I was about to press the accelerator.

Why could the idiots who designed the system not integrate it with the SatNav and also enable a longer delay before the system works.

Rant over.

[happy days]

The Porsche Stop Start tech is junk.

The absolute best feature is the inhibit switch that stops the damn system from working.

Or you can just put the car in Sport mode and that also inhibits the system.

I got totally fed up of slowing down at a Stop junction only got the damn stupid system to then stop the engine just as I was about to press the accelerator.

Why could the idiots who designed the system not integrate it with the SatNav and also enable a longer delay before the system works.

Rant over.

Agreed.

[RickZ]

All stop/start functions should have the option in settings to switch off stop/start permanently. With my Audi's the art with start/stop was to come to a halt and reduce pressure on the break peddle before stop/start kicked in which overrode the auto stop function whist still applying the brakes. I've spoken to colleagues who own other brands of car, they tell me stop/start also works this way on their vehicles. I assume in these cases it's a case of sensing when a car stops and the brakes is applied, if the system thinks the brake hasn't been applied it won't stop the engine. I must admit it's an easy process to get used to, after stopping I used to relax pressure on the brake pedal slightly , it became the norm, I'll have to try it on my Macan.