Looks like there's some confusion and unanswered questions here, so I'll try to clear up what I can:
- Auto Start/Stop was introduced in 2011.5 M3s, i.e. September 2010 production and later. It's now standard equipment and it didn't get introduced on any other BMW models at that time, even the normal 3ers. The only other models that currently have it in the US are the ActiveHybrids; I believe 3ers in other markets have had it for a while though.
- It defaults to DISABLED on startup on US cars, but I've heard other markets default to having it ENABLED, such as Australia. Not sure about Canada, UK, Germany, etc but I'm curious if anyone knows for sure.
- You CAN change this behavior, but you have to do it via coding with special software and an OBD-II cable. Your startup options are Enabled, Disabled, and Last State. I personally coded Last State, which I think should be the default startup mode in all markets. That coding takes about 3 minutes, so anyone who quoted several hundred pounds is gouging like nobody's business -- and therefore should get nobody's business.
- It will only kick on if the engine has reached operating temperature, the cabin is at the desired temperature set on the A/C, the outside temperature is within a certain range, and a few other parameters, so having it enabled doesn't guarantee your engine will stop every time you do.
As for what I think of it, I agree there's nothing wrong with trying to save gas. The fact that M3 owners are probably better off financially on average doesn't mean that, all things being equal, they wouldn't mind saving some cash on gas or being greener. It's not like you lose 50 horsepower out of the deal. I thought about engine wear and tear myself, so if I know I'm only going to be stopped for a few seconds, I'll keep the clutch down so prevent it from kicking in, and if I'm going to be in actual stop and go traffic that actually stops and goes frequently as opposed to gridlocked stop and go, I'll disable it entirely. For times when I'm only coming to a stop occasionally and the stops last a fair amount of time, why not save some gas? Yes, some people have looked at me like I stalled my car, but I'm secure enough not to worry what some random person in the car next to me thinks of my 6MT skills.
Last edited by jphughan; 07-05-2011 at 07:46 PM.