[E92inNC]

So I'm not entirely sure how stop-start works. Pretty much the only solid fact I know about it is to stop emissions while the car is at a dead stop-i.e. traffic light. Curios for future references.

Does the engine stop completely and have to be the equivalent of warm starting each time? Doesn't the feature wear out the battery/starter? Does the A/C stop working bc the engine isn't running? Anything else you can tell me that I didn't ask would be much appreciated.

Personally,when I buy a car later on-used or new- I would have it disabled from the factory or probably would pass if I went to test drive it and it was enabled. Does anyone here with current ten leave it enabled or did you disable it?

[cpie168]

Why disable it? Doesn't it save gas consumption? I like to have more money in my pocket.

[E92inNC]

Originally Posted by cpie168

Why disable it? Doesn't it save gas consumption? I like to have more money in my pocket.

If it does a warm start upon lifting off the brake pedal there might not be savings from dumping in fuel to start vs idling for 30 seconds at 600 rpm. Lets say I idle 50 hrs at lights every year, I would trade off the 10 or so dollars it costs to not have it stopped. Plus from the f30 loaners I really didn't like the shudder when it restarts.

[smallseafishie]

Stop Start can be disabled by a button next to the engine start button. I'm not sure about defaulting it on or off...

When engine is off, AC stops working - fan continues to blow at a reduced speed but the temperature gets warmer the longer it is stopped. The engine will eventually kick back on to cool the car down some more if stopped for a longer period of time.

The starter is used to start the car - supposedly better engineered to support the higher cycling.

[Vegetable]

Originally Posted by sxyblue

So I'm not entirely sure how stop-start works. Pretty much the only solid fact I know about it is to stop emissions while the car is at a dead stop-i.e. traffic light. Curios for future references.

Does the engine stop completely and have to be the equivalent of warm starting each time? Doesn't the feature wear out the battery/starter? Does the A/C stop working bc the engine isn't running? Anything else you can tell me that I didn't ask would be much appreciated.

Personally,when I buy a car later on-used or new- I would have it disabled from the factory or probably would pass if I went to test drive it and it was enabled. Does anyone here with current ten leave it enabled or did you disable it?

Since no e9x has this feature, you'd likely get more accurate responses from F30 post.. But as a F32 owner, this feature is ridiculous and saves maybe 0.003 MPG with 50/50 highway/city driving. Nobody I know with a F3x actually uses this feature, nor do I.

[Efthreeoh]

They call it ASS for a reason...

According to BMW, the starting system is beefed up to handle the duty cycle that's comes with the start/stop capability. IIRC BMW uses a larger deep-cycle battery and a stronger starter motor. That said, it's still more wear and tear on the components. One needs to understand that passing ridiculous levels of fuel consumption mandated by Governments in Europe and the USA drives automotive design to pass fuel consumption and emission tests (nee Volkswagen...) rather than benefit the consumer with highly reliable and low operating costs. The starting system is robust enough to get past the warranty period, then when it fails it is on the consumer to pay the high price repair bill, which in the end saves the consumer no money.

Mazda's system is pretty neat, when the engine shuts off, it stops at a cylinder cycle where upon restart the computer injects fuel and fires the plug just for the cylinder that is at the power stroke cycle, which aids in starting the engine and reduces the burden on the starter.

It seems to me the system should be actively engaged rather than actively bypassed.

[gotturbo]

I remember when I had my '13 X3 reading that if you took it to the dealer they would be thrilled to reprogram it to default off instead of on. I never did it, but I was going to if I had kept it.

[floydarogers]

1) Good answers on durability (beefed up starter and ring gear)
2) The savings is more substantial than some would have you believe. In the city cycle it's more in the 0.5-1.0 mpg range. The iDrive system can track it in Eco Pro mode and will tell you how much it's saving.
3) The dealer is not able to disable the system entirely. However, if you complain hard enough they are authorized to set it to "Remember last mode": if you turn it off, it will remember that setting and not default on on every engine start.
4) It's easy to get used to. Like any new feature (3-click turn signals for instance) it takes a bit of experience.

There are some situations where disabling it makes sense: entering a garage where you have to stop momentarily to flash a card, or take one, to get the gate to up. Etc.

[Dark_Knight_335]

Bullshit gimmick. My gas mileage was no better on my loaner 328 this month. In fact, it seemed worse.

Besides, that split-second between putting my foot on the gas and actually accelerating in the middle of a busy, deadly intersection just doesn't sit well me.

Eco mode itself, however, seems worth its salt.

[DF]

I find it annoying and useless. My next car will have it programmed off.

[E92inNC]

Originally Posted by Efthreeoh

They call it ASS for a reason...

According to BMW, the starting system is beefed up to handle the duty cycle that's comes with the start/stop capability. IIRC BMW uses a larger deep-cycle battery and a stronger starter motor. That said, it's still more wear and tear on the components. One needs to understand that passing ridiculous levels of fuel consumption mandated by Governments in Europe and the USA drives automotive design to pass fuel consumption and emission tests (nee Volkswagen...) rather than benefit the consumer with highly reliable and low operating costs. The starting system is robust enough to get past the warranty period, then when it fails it is on the consumer to pay the high price repair bill, which in the end saves the consumer no money.

With the way cars are being built bc of emission laws, I think I'll probably be leasing when it comes time to buy new unless it's something like a Civic.

Originally Posted by floydarogers

3) The dealer is not able to disable the system entirely. However, if you complain hard enough they are authorized to set it to "Remember last mode": if you turn it off, it will remember that setting and not default on on every engine start.

I thought I read somewhere that if you buy/lease new, they give you the option of having it disable from the factory? Whenever I've had the loaners I have pressed the button above the start button to keep it disable but somehow after starting it a few times it'll randomly go back to stop-start and I have to press it again.

[krhodes1]

My M235i has it, doesn't bother me a bit. BUT, my car is a stick, which means I have much more control over it. With the manual transmission, it will only shut off the engine if the transmission is in neutral and the clutch released. So that eliminates 95% of the bothersome extra shutdowns in traffic that happen with the automatic. When I have had automatic loaners/rentals, I disable this feature in stop and go traffic, and turn it back on when in areas with lots of traffic lights. I think it works quite well overall.

[Eddien123]

Start stop is so stupid. In the long run it hardly affects fuel economy. Mazda has a very good system that stops with a cylinder at top dead center with the fuel air mixture already compressed. Instead of the starter restarting the engine, that spark will fire to restart it. I don't care how strong they make the starter, it is unnecessary wear and tear for very little reward.

[Kevinl]

very stupid system not to mention it would never work here when its 110 in the summer