Tesla's range numbers for the Model S assume about 300Wh/mile average consumption. My average consumption so far over not quite 8,000 miles is 315Wh/mile.
It's hard to cheat in an electric car. Few people care about efficiency directly, but most electric car drivers care deeply about range, and range is just battery capacity multiplied by efficiency. If Tesla were cheating so they could lie about efficiency, Tesla owners would notice pretty much right away that they're not achieving the range they should.
The only practical way for Tesla to cheat would be to ship a larger battery than they say they do, and then fudge the numbers from there. Given the current cost of batteries, this would be an incredibly expensive cheat, and it would be tough to hide from the tinkerers who tear down battery packs to see how they're built.
It's hard to cheat in an electric car. Few people care about efficiency directly, but most electric car drivers care deeply about range, and range is just battery capacity multiplied by efficiency. If Tesla were cheating so they could lie about efficiency, Tesla owners would notice pretty much right away that they're not achieving the range they should.
The only practical way for Tesla to cheat would be to ship a larger battery than they say they do, and then fudge the numbers from there. Given the current cost of batteries, this would be an incredibly expensive cheat, and it would be tough to hide from the tinkerers who tear down battery packs to see how they're built.