dmicah

I like it. Left mine on. Anyone else notice that you can modulate whether the engine shuts off at a stop light based on how hard you press the brake pedal? A light press on the pedal (enough to hold the car in place) will not engage the stop, but a heavier one will.

idale

Yes, though you have to be very light at least in my experience. Doesn't take much more than required to barely hold the car back from creeping to trigger. Sometimes I've not noticeably depressed the pedal further at a light and it goes from not trying to activate (no start-stop symbol next to the gear selection) to engaging. Figure I must've just barely feathered the pedal into activation range or something.

Whenever I'm worried about it engaging when I really don't want it to, I'll just hit the button as I'm coming to a stop just in case. Otherwise, it restarts so quickly it's not that much of a delay (more the small bit of wasted fuel in cutting out and very quickly having to come back on).

dmicah

Interesting. My pedal seems less sensitive than that. Pretty easy to keep it from engaging, if anything it's more likely not to engage unless I press a tad harder than I would think to.

Michael92673

This feature is in response to the CAFE fuel economy targets. By installing this feature it is easier (less expensive) for an auto manufacturer to reach the CAFE targets. Obviously you can turn it off just as you can floor it anytime you wish (driving your fuel economy down) so these CAFE targets are somewhat artificial.

imdakine1

Thanks for sharing the potential impact on the starter @davey001. I was a bit concerned with it since I do a lot of in town driving and we have a lot of stop signs and signals. It does get slightly annoying at stop signs when it is four or five cars deep. I agree that you cal learn a bit on how much pressure to use on the gas for it to truly stop or to have it idle. I was also impressed that you can hit the button anytime to turn it off and turn it back on while driving. --- I always get a bit worried about messing with things to much when the car is in motion etc...

Has anyone ever put the car in park and almost forget to turn the motor off? I did since once I go to park the motor shuts down and I almost forget the engine is still on etc... My brain needs to be retrained a bit.

idale

Everything wears out from use (or even disuse), so don't worry about it. The starter and battery are both designed with the start-stop system in mind and are able to handle the increased load. Obviously leaving the system active will wear more than leaving it off, but you can further reduce wear by not starting your car at all and just walking more (though that'll increase wear on your legs and shoes).

rbradleysd

I really like the start/stop on my Q5 (anyone else notice how the A/C fan slows down in the speeds when it cycles off? I count 5...4...3...2...1 LOL)

Question thou. Do we think it will create any long term engine damage/excess wear? The only worry I have is premature engine/transmission wear

idale

My A/C fan doesn't turn off, it just slows to avoid using as much power. Seems to do so fairly quickly, too, going from potentially a 4-5 to a 2 or so without noticeably "stepping down".

And if anything, I'd expect less engine wear from all the time the engine spends being off. I think it's the battery and starter that have to bear the brunt of the work in starting the engine and the engine's just along for the ride (but could be wrong). Regardless, though, the start-stop isn't something just slapped on after the fact, the whole system has been designed with it in mind (and vehicles equipped with it have the necessary heavier-duty components to support increased start load). It's also been in use in Europe for quite a while and I at least haven't seen any complaints due to damage caused by the system (just complaints by people who don't like it and due to configuration over there can't permanently disable it like we can here).

imdakine1

The audi service manager I spoke with yesterday has the technolgy in a Porsche that he owns. He doesn't use it since he doesn't like it. He seemed to think that it "shouldn't" be a major issue as it sounds like it is becoming more common in a lot more cars in the US. As others have said this is clearly a tested concept that has been used for a longer time in Europe. I'll likely keep it on most of the tone and just turn it off of I see a stop sign with 4-5 cars deep since these are the times that I get most annoyed. I don't mind it as much if I am going to stopped at a signal.

idale

There seems to be resistance to it, but I expect a lot of that is people disliking "different". We aren't used to the engine shutting off and restarting (other than in a hybrid where it's different since there's the electric engine that'll be used for takeoff), so some people don't like it because of that. I think it's mostly a matter of getting used to it and how well it's executed.

Audi seems to have done a good job since the engine comes back quickly and you can start moving immediately (though it does take a few seconds to have full power available, but I've always had enough to get me going satisfactorily) and there's not a lot of noise/vibration with it (other than the rumble and vibration from the TDI stop). I see a lot of complaints about BMW's version (and no compliments ever), though, so not everyone's done it very well -- but hopefully over time that changes and every manufacturer has at least a reasonable-enough implementation.