Near as I can tell comparing my Teslafi Wh/Mile data for my commute I gained at least 5% after moving to the VS08's in 19x8.5+30 fitment from the stock 20" setup. I also moved to snow tires and its been colder (running heat more), so the gain may be greater. I'll need more sample data to be sure given each day's drive differs based on snow on road, temp, traffic, my inclination to push the fun pedal, etc. Some drives show double-digit gains compared to same drive a month earlier on stocks at nearly same max speed, ave speed and fan speed setting of car, so I'm hopeful it does turn out to be 10%+.
Edit, another thing that may point to 10%+ is that I have to keep my car outside and lately even with pre-conditioning battery and car (charging right before commute) I do have the reduced regen msg, which I never got back when I had the 20"s on. Since my commute into work drops 2000ft in elevation the first 7 miles, I likely am not gaining as much back in regen with the colder weather as I did prior.
