The Model S 85 top speed changed from 125 to 140 mph after the D announcement. Nice But what design change made it possible? Two guesses: 1. taller gearing. Is the taller gearing borrowed from P85D so that they only need to make one version of rear DU gearbox for both cars? 2. just a better inverter that gives more torque at high rpm, still with the old 9.73:1 gearbox. What is it? Let the speculation run wild!