Tesla Motors Club

I used my G-tech meter today to get 0-60 times. I made ten runs, the best being 4.255 and 4.297, the rest were above 4.3. I did the first 3 or 4 runs with no power braking. The next couple of runs used power braking and I saw no improvement. The final 3 or 4 runs used power braking and performance mode. I did not do a performance charge. I started with a full standard charge. The question is, where did those three or four tenths go? I learned that 100 pounds is worth about a tenth of a second so that shouldn't be the problem. I had TC off but had no wheel spin. My car is a 1.5. Could a performance charge make that much difference? Any other ideas? Have any of you guys got 0-60 times for your cars?