Auto Stop-Start: Enable/Disable?

[Foxhound5366]

I have heard stories of ring gear failures at least one of which was in a BMW like foxhound's and likely attributed to too many start cycles.

Oh great, you had to single me out You'll be happy to know that my wife is already my happy assistant in deactivating SS as soon as we start out on a journey, so that'll have to do until I get the car into a workshop to see if they can do the software update mentioned earlier that will help the car remember my last setting.

 

[JJCT]

So I tried to leave the SS on yesterday. Driving the car for 5 months now I thought since I'm more familiar with the car now maybe it will be a different experience than when I first started.

It did not last long, after about 30 minutes I switched it off. Although not a diesel like koogs wife's car my car does also have a bit of a rumble when it turns on, maybe in eco mode it would be better but then that just defeats the purpose of the car.

 

[upup]

Wonder if the starter is also bigger , like the batteries, in such a car.

 

[SauRoNZA]

Wonder if the starter is also bigger , like the batteries, in such a car.

Yes specially upgraded starter in auto start/stop cars.

 

[FiestaST]

ICYMI...Ciro from Cars.co.za was *not* impressed with the SS implementation on the Mahindra TUV300

[video=youtube_share;syZvTvy4Bj4]http://youtu.be/syZvTvy4Bj4[/video]

 

[Foxhound5366]

ICYMI...Ciro from Cars.co.za was *not* impressed with the SS implementation on the Mahindra TUV300

[video=youtube_share;syZvTvy4Bj4]http://youtu.be/syZvTvy4Bj4[/video]

I'm *not* impressed how SS makes my car feel like a Mahindra TUV300 lol.

 

[FiestaST]

Here is the SS button location for the upcoming Alpine A110:



https://mybroadband.co.za/vb/showthread.php/874746-2018-Alpine-A110

 

[Sinbad]

on a turbo car this could be a problem especially if the turbo is hot and the car just switches off, with nothing to pump the oil you can expect damage to occur

You'd think the designers would consider this... and perhaps have an electric oil pump or similar? I know my Cupra had an electric water pump that cooled the turbo when you switched the engine off

 

[Billy]

Surely there are two reasons for the introduction of this "Feature"?

1: Fuel saving.

2: Reduced emissions.

I would think that the reduction in emissions is the primary reason.

 

[Masataka]

Surely there are two reasons for the introduction of this "Feature"?

1: Fuel saving.

2: Reduced emissions.

I would think that the reduction in emissions is the primary reason.

It's the meet emission requirements in various countries, but because it was only done for legal reasons, it's a half-assed implementation.

 

[kripstoe]

It's the meet emission requirements in various countries, but because it was only done for legal reasons, it's a half-assed implementation.

Would you please share your own analysis based on engineering experience for this statement?

 

[kripstoe]

You'd think the designers would consider this... and perhaps have an electric oil pump or similar? I know my Cupra had an electric water pump that cooled the turbo when you switched the engine off

Indeed. Electric pumps are active during stop/start.

 

[Masataka]

Would you please share your own analysis based on engineering experience for this statement?

The only real change that was made, when this tech first came out, was a new battery that could handle the additional cycles, but the powertrain was never overhauled to integrate efficiently with it.

Even in new cars, the majority don't run any sort of auxiliary cooling to keep components in check while the car is off, with the assumption that people won't sit idle for too long - you only need common sense to understand that it adds additional wear and tear to the powertrain (above what would happen to a car without the tech).

It was an easy answer to new legislation, and will eventually function effectively, or be replaced with a new system.

Plus, who wants their aircon to cut out every time they stop?

 

[Arthur]

I really wish I could permanently switch this off. Such a pain to press the A button every time I start the car.

In the end I blame the enviro-loons in European and North American governments. They're on a rampage to ruin all human life.

 

[f2wohf]

The only real change that was made, when this tech first came out, was a new battery that could handle the additional cycles, but the powertrain was never overhauled to integrate efficiently with it.

Even in new cars, the majority don't run any sort of auxiliary cooling to keep components in check while the car is off, with the assumption that people won't sit idle for too long - you only need common sense to understand that it adds additional wear and tear to the powertrain (above what would happen to a car without the tech).

It was an easy answer to new legislation, and will eventually function effectively, or be replaced with a new system.

Plus, who wants their aircon to cut out every time they stop?

When idle too long, mine restarts the engine for 10-30 seconds and then cuts it again, I don't know if it's for the aircon or the cooling though.

I should try with the aircon off and see if it still does it.

 

[Masataka]

I really wish I could permanently switch this off. Such a pain to press the A button every time I start the car.

In the end I blame the enviro-loons in European and North American governments. They're on a rampage to ruin all human life.

It's usually quite easy to code it out of the car if you visit an independent mechanic with the right software.

 

[Masataka]

When idle too long, mine restarts the engine for 10-30 seconds and then cuts it again, I don't know if it's for the aircon or the cooling though.

I should try with the aircon off and see if it still does it.

Yea, usually it's to help settle the temp inside the car, or if it's turbocharged, to circulate fluid (some cars have auxiliary electric pumps for this).

 

[f2wohf]

Yea, usually it's to help settle the temp inside the car, or if it's turbocharged, to circulate fluid (some cars have auxiliary electric pumps for this).

It is turbocharged, I'll try without aircon next time I'm in heavy traffic.

 

[Archer]

Even in new cars, the majority don't run any sort of auxiliary cooling to keep components in check while the car is off, with the assumption that people won't sit idle for too long - you only need common sense to understand that it adds additional wear and tear to the powertrain (above what would happen to a car without the tech).?

Like when the car is parked? What cooling does a car need when it is parked, vs engine off at the traffic lights?

 

[qscwbt]

I don't like it. To manufacturers this is great to juice up efficiency scores. but in real life this has no place.

Starters
Cost and replacement cost of beefed up starters.
Excessive wear as this starters bendix, solenoid, (on some car reducer gear system) and solenoid now work 100 times harder.

Battery
Car require a much bigger higher amperage battery this is higher cost and the bigger current demand creates more heat and quicker battery failure

Main, big end bearings and most moving parts that require oil.
When the engine starts, there’s a point before the two surfaces become separated by the oil film called the ‘boundary condition’, where the crankshaft is spinning, but there’s metal-to-metal contact between the bearing surfaces.
This is when most wear takes place. Fitting stop-start means the boundary condition (and metal-to-metal contact) could exist perhaps 500,000 times in the life of the engine instead of 50,000 and normal bearings would wear out long before that.

Turbo
On a wide open throttle acceleration exhaust temperatures (egt) can go as high as 900 degrees. When the engine suddenly stop there is no water cooling or oil to the turbo bearing. (bad boundary condition again) and the little oil film in the turbo at such high temps burns to a crust.

Cooling system

When you switch of a hot car the temps will climb before it starts to cool down. This excusive heating cooling cycle now happens more, this will increase the pressure in the cooling system with more cycles that will wear all water pipes due to more expansion and contraction cycles.

Engine oil

Oil film left on hot surfaces will make a crust. Thus you would need a good oil to reduce this. The oil will also not last as long and need more detergents to keep surfaces clean. You going to get more gung in your engine.

AFR

When you start your car it runs richer (like a choke). This higher Fuel ratio causes piston wash as it cleans lubricating oil of the piston. This leads to more wear. You also have more fuel contamination in the oil.


I do know some stop start function uses a system by were is fuels a cylinder and have the piston at compression. to start the ecu fires the plug and the car is started with ignition of the mix in the combustion chamber. Al this does is reduce the wear on starter and battery.

Personally I would not want it.