50pascals

+1 I like the way you think.

kevrhof

I'll agree that its not more than those vibrations, merely I'm saying it cant be good in say traffic use. Just like slamming on the gas and the brake in traffic wouldn't be good either, causing the vibrations you stated

radarguy

I think the intent of this device is to increase gas mileage not necessarily to reduce emissions. In my case it probably increases both emissions and gas consumption. First of all, most of my stops are at stop signs. So the stop is 1 or 2 seconds. No gas saved here. The stoplights here rarely stay red for more than 45 seconds. Not any gas really saved. When I stop at a light, if I release the brake pedal pressure ever so slightly (not enough to let the car move) the car restarts. It seems this is the normal situation when I stop for a light. No gas saved here either. Finally, when I come to a stop sign, then apply the gas when it is my turn to go, the car hesitates while it restarts. Very unnerving. All in all, I look at it as a device designed to legally pass the EPA tests, doesn't do what it is supposed to do in the real world and undoubtedly increases wear and tear.

the_duke

Testing has shown that it does indeed improve fuel economy. I read a lot of posts in all sections of this forum and I've yet to read of anyone having a starter replaced. It certainly takes some getting used to but I don't mind it at all.

radarguy

That's interesting. Can you reference some test other than the EPA tests which do no represent real world usage?

Sportstick

NHTSA provides a CAFE credit to VAG for having *** default to "on" with each start, which A6 just started taking advantage of in 2016MY. This is a primary motivation for an OE, who can get credits for essentially no incremental investment nor variable piece cost, assuming the component upgrades were already included when the non-defaulting-to-"on" system was launched.

I'm not sure of the implication of the first comment above. A small and inherently biased subset of A6 owners (those who participate on a forum) may not have reported durability issues for feature whose rate of usage is only now significantly increasing with the new default programming in the 16MY. What do we conclude from that? If one plans to keep the car for 5-10 years, I think reasonable experience supports that multiply more starting cycles will have some unknown future effect on batteries, starters, etc.

50pascals

It reduces fuel usage and emissions at the expense of wear and tear on the car and occupant comfort.

This is pollution displacement. We no longer pay for our energy at the gas pump, or generate emissions from our tailpipe. We buy or embodied energy in expensive parts that produced emissions somewhere else. The net energy balance is likely negative.

Or perhaps better said, will the gas you saved pay for 1 battery and 1 starter?

audi bug

Stop-start system is not that simple implementation as you think.
I don't like it and prefer to turn it off because of annoyance but can live with it.
I was in Europe for a couple of weeks in October and had a Volvo C40 with a diesel engine as a rental car. I was shocked how aggressively it was implemented for a diesel engine. It stopped while engine was cold and surprised me every morning.
Our A6 takes a while before it begin stop-start after cold start. It appears battery charge level and engine temperature are big factor.

A decent read here.

Do Stop-Start Systems Really Save Fuel? | Edmunds.com