Unofficial figures (thanks Martin ) gives us 3.86 with traction control on. Others have speculated 3.7ish with traction off and maybe higher with a Sports Battery Pack fitted (higher power density/lower energy density). My initial thoughts are that a Sports Battery would require a firmware upgrade for both the ESS and the PEM. You couldn't simply swap the cells. So would have to be a company endorsed and licensed upgrade. I don't expect Tesla to support running the Roadster at the extreme of the envelope. Tesla shouldn't stress the transmission. Quality and reliability is crucial for the long term success of the company and an often cited benefit of EVs is a simpler, more reliable drivetrain. I think we can expect Tesla to choose to electronically limit this acceleration to a longer value, much like the 125 mph limit to the top speed. Even 3.9 (official) with TC on would still be a remarkable achievement for the first EV from a company of 250 employees. Car reviewers would still be free to get faster times with TC off.