[samej]

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Did a search on Google and came up empty - does BMW quote how much fuel is used for an re-start by ASS vs just idling? So for instance if ASS activates for 3s, would I have been better just idling? Inquiring Minds Want To Know!

[Cio]

I was curious about the start-stop technology also. Though i couldn't anything about bmw, there was this video that kinda reviewed similar technology.

According to the tester's records, you save about 10% of gas using the technology. I know it isn't a bmw on the video, but i'm giving bmw the benefit of the doubt of having a better system than the one used.

Disclaimer: i haven't tested it personally.

video about start stop technology:

[ToyotaBMW]

I think it depends on if you live in the city or the countryside. If you live in stop and go traffic of the city I think it could be significant.

[samej]

There's a blurb on BMW's site too, claiming about the same. I'd like to know the equivalent idle consumption so I know when to override and when to chill in my morning crawl.

Maybe 5-7 years ago I recall a quote from a dude at MB saying a full start was the same as 10s of idling.

I'm crawling 4.6 km in 15 minutes dropping Number 3 to school in the mornings. I need to entertain myself somehow...

[Sedan_Clan]

Originally Posted by samej

There's a blurb on BMW's site too, claiming about the same. I'd like to know the equivalent idle consumption so I know when to override and when to chill in my morning crawl.

I rarely used ASS in my M3's, and I haven't really used ASS in the F30 either. I will probably use it in really congested areas, but disable it when traffic is non-existent or moving relatively freely.

The bigger question is how much gas is saved using ECO-PRO mode!?? The car is sooooooo damn sluggish. I may see how my mileage increases on the freeway using ECO-PRO, but I can't deal with it on the street unless there are no other cars around.

[Dan_335i]

Originally Posted by Sedan_Clan

I rarely used ASS in my M3's, and I haven't really used ASS in the F30 either. I will probably use it in really congested areas, but disable it when traffic is non-existent or moving relatively freely.

The bigger question is how much gas is saved using ECO-PRO mode!?? The car is sooooooo damn sluggish. I may see how my mileage increases on the freeway using ECO-PRO, but I can't deal with it on the street unless there are no other cars around.

M3 has ASS?

[Sedan_Clan]

Originally Posted by Dan_335i

M3 has ASS?

Yep!

[snowghost]

Originally Posted by Sedan_Clan

I rarely used ASS in my M3's, and I haven't really used ASS in the F30 either. I will probably use it in really congested areas, but disable it when traffic is non-existent or moving relatively freely.

The bigger question is how much gas is saved using ECO-PRO mode!?? The car is sooooooo damn sluggish. I may see how my mileage increases on the freeway using ECO-PRO, but I can't deal with it on the street unless there are no other cars around.

My morning commute on surface streets has some really long lights that can take 2 or 3 cycles to get through. Using ASS I can get my MPG to 20-22. Otherwise with light traffic unless I'm at a fresh red light I don't bother.

Tried ECO PRO for 30 seconds once and immediately went back to Sport+

[RoundelM3]

I had my car programmed to "remember last setting" for ASS. It's been shut off since then. Makes zero sense where I live.

[elistan]

Originally Posted by samej

Did a search on Google and came up empty - does BMW quote how much fuel is used for an re-start by ASS vs just idling? So for instance if ASS activates for 3s, would I have been better just idling? Inquiring Minds Want To Know!

I can't find the source now, but I've read that starting the engine takes as much gas as four seconds of idling.

[Elk]

Correct.

[SomeRandomer123]

Apparently if your stop is 4 seconds or longer, it's worth the ASS.

Ah, beat me to it above!

[hmc]

What about starter life and potentially battery life impact?

[Sedan_Clan]

Originally Posted by hmc

What about starter life and potentially battery life impact?

I think there is a separate starter for cars with ASS. At least it was that way on my E9X M3.

[adge7]

Originally Posted by elistan

I can't find the source now, but I've read that starting the engine takes as much gas as four seconds of idling.

It's in the user manual - There's a mention of turning off your vehicle during prolonged stops, but that 4 seconds is effectively the break even point.

So I think 4 seconds is the go, that's what I work off.

[elistan]

Originally Posted by adge7

It's in the user manual - There's a mention of turning off your vehicle during prolonged stops, but that 4 seconds is effectively the break even point.

So I think 4 seconds is the go, that's what I work off.

It's not the US version. Can you post a pic of your version?

[elistan]

Originally Posted by hmc

What about starter life and potentially battery life impact?

BMW says certain vehicle components may experience increased wear. They don't say which components, or how much increased wear.

[adge7]

I'm unable to attach the file. Here's the part from the user manual:

Switch off the engine during longer stops
Switch off the engine during longer stops, e.g., at traffic lights, railroad crossings or in traffic congestion.
Fuel savings are achieved after the vehicle is switched off for only approx. 4 seconds.

EDIT 2: apparently it did attach, well there you go

[CKau]

Maybe they should program it so that we decide if we want to kill the engine. i.e. MSS instead of ASS. Some stops are unpredictable and my engine stops for less than 4 seconds.

I find myself only activating ASS if I "think" my stop will be more than 4 seconds (and only in heavy traffic). ASS not worth it in my opinion if it keeps killing the engine every min for less than 10 seconds... imagine the battery drain and component wear !

[elistan]

Originally Posted by adge7

I'm unable to attach the file. Here's the part from the user manual:

Switch off the engine during longer stops
Switch off the engine during longer stops, e.g., at traffic lights, railroad crossings or in traffic congestion.
Fuel savings are achieved after the vehicle is switched off for only approx. 4 seconds.

EDIT 2: apparently it did attach, well there you go

Thanks for that. Very interesting how the manuals from two different countries, can vary, eh? The US one only gets as specific as "a few seconds." Weird.

[Sedan_Clan]

Originally Posted by CKau

Maybe they should program it so that we decide if we want to kill the engine. i.e. MSS instead of ASS. Some stops are unpredictable and my engine stops for less than 4 seconds.

I find myself only activating ASS if I "think" my stop will be more than 4 seconds (and only in heavy traffic). ASS not worth it in my opinion if it keeps killing the engine every min for less than 10 seconds... imagine the battery drain and component wear !

ASS isn't really unpredictable.....at least in manual transmission cars. You have to put it in manual, release the clutch and press the brake for the car to shut off. The moment that the car begins to roll or you depress the clutch the car will start again.

[jdong]

Originally Posted by Sedan_Clan

I think there is a separate starter for cars with ASS. At least it was that way on my E9X M3.

No, there's not on the new F30 design unfortunately. It's just a bolstered starter motor. If you get HK audio, the car has a "clean" 12V rail that it actively maintains to prevent your sound from cutting out / popping when a start coincides with a subwoofer boom.