AdamNJ

Does anyone have experience test driving one of the new models that include the Mild Hybrid (MHEV) 48v battery system with belted alternator starter (BAS) used for start / stop functionality? This is one of the things I'm anxious to know about for the new A6.

My current vehicle does not have start / stop functionality (the gas engine turns off when you stop at a traffic light). I've rented a few cars over the last few years and I hated the stop / start systems they employed, mostly because of the delay and vibration of restarting the engine. Those were all using the normal pinion starter method.

Audi's advertised this BAS system as no delay, no vibration from the materials I've seen. I've yet to find a test drive type video on YouTube where someone talks about the system and whether is really is as good as Audi says. The test drive videos don't mention it or you get the Audi animation about how the system works.

TheTurtleBoy

I have read every review about the A6 and A7 I could find including foreign sources and have not seen anything negative about the start/stop system. Most just mention that it has it and the 48v battery is used for it. Digital Trends said the most about it that I could remember, it says "In this case, electrification takes the form of a mild hybrid system consisting of a belt-alternator and a 48-volt electrical system fed by a lithium-ion battery hidden under the trunk floor. The technology boosts fuel economy while helping fire up the engine faster and more smoothly after the stop-start system turns it off. The hybrid system’s presence is virtually indiscernible in normal driving conditions. It interferes when needed without fundamentally changing how the A6 drives, which is precisely how Audi envisioned it.".

I'm sure once the car is available in the US we will get more detailed reviews and any stuttering, vibrations, etc. will come to light.

Doug2.7

I read the same. I also read that the Audi senses the car in front of it moving and starts the electric system at that time. I too have rented start stop cars and they suck. Audi seems to have overcome that concern according to one of the salesman at the dealership who attends all the workshops for the A6... He knows a lot of stuff I have not read anywhere...

BTW, the A6 build is still messed up. The interior colors are wrong as well. Weird they would launch that build and be so far off the mark. Left hand needs to talk to the right one...

AdamNJ

a8 review in usa: https://www.engadget.com/2018/10/19/...udi-a8-review/

angrypengu

The other thing to note is that the high speed deactivation of the engine as in Europe (when coasting to a stop) is not an active feature in the A6/7/8. This is taken from the article from the A8 forum that states something along the lines of "4 things the A8 won't have at launch". That's where I learned that bit.

This is disabled, for some reason. Probably some dumb law.

TheTurtleBoy

I don't think it is a law, I read in a review it is because the engine didn't start up fast enough for the way US drivers drive on highways.

angrypengu

Based on the Engadget review if it can start so fast and so seamlessly from stop-go, wouldn't this issue not be a problem?

I've seen some Youtube video about this system in a drive POV - AutoNL or something or other. It was pretty darn seamless. But anyways, we can both theorize but we don't know why for sure, but we do know it's disabled for us.

TheTurtleBoy

No, I wouldn't think that necessarily means anything since that is from a stop and not while cruising on a highway where the throttle would be filly engaged at any time and the drive is expecting the car to react immediately. I will see if I can find the article.

angrypengu

Good point, that and the transmission has to get up to speed to get synced with the engine.

But yes, if you can find it and you wouldn't mind sharing it, I'd love to have a read.

TheTurtleBoy

From the article, it was concerning the A7 but same system: "European models also benefit from a coasting function that shuts off the engine when not needed between 34 and 99 mph to save fuel (0.7 liters per 100 kilometers to be exact), but that system was deemed to restart a tad too slowly when re-engaging the throttle for American tastes."

https://www.motorauthority.com/news/...tion-in-africa