Hi all,
I would second that it works only under the right conditions. For the first few weeks of ownership, mine worked well and as it should. After a lot of really short trips, lots of stop/start and some really cold temps, it didn't work at all. I got the low battery voltage light once and I knew that was the culprit.
Then we drove to Colorado and back and it worked again. Funny how 1100 miles will charge a battery.
It stopped working again at one point, then the dealer did the software update and it seems to work again as it should. I really do think it saves some gas, but it does get troublesome in stop and go traffic. I will disable it on my commute home if it looks like I will be bumper to bumper with lots of stops on the express way. The rest of the time, I just leave it on and welcome that it is functioning as it should. But to be honest, I play the game of mileage almost every day. I have not really had any trips less than 20mpg with my XC90. And I can almost always get 25mpg if I think about it. A few trips, even some longer ones, (50-150 miles at a time) have got me over 29mpg. One 15 mile trip home last week got my best mileage ever at just over 33mpg. Like I said, it has become a game to me to see how well I can do.
I set up a custom program based on the Ecco mode. I also run 93 octane almost every fill up. I will run pretty light most of the time, just me in the car and maybe the dog. I also try to anticipate stops, use light acceleration, but I see 75+ speeds every day on my way to work going in and out of traffic. It truly is a great commuter car: soft air suspension, heated/ventilated seats and Bowers and Wilkins cranked with classical music. It sure deadens the outside world.
Rob