Hi Hiroshiy:
After 8K miles on my S04 Pole Positions, my Wh/mile is 320 with a P90D Ludicrous which is pretty darned good. I took the stock tires and wheels off on day 1 when I got the S so I have no point of reference. I will be putting back on the stock all season tires in November so I will see how they run. However, I suspect that cold weather and its effects on Wh/mile may mask any savings IF there is any, the S04's are quiet and seem to be efficient too.
I have been doing on average, 56 miles per day since owning the S so I am not really a high mileage driver where 10% would really mean something. We have been going on quite a few long drives and trips which has attributed to such a high daily rate. Normally, I am at about 40 Miles per day. When my recharge starts at 5AM it is usually done between 6:30 and 7AM at 40A.