But don't 100-plus-mpg EVs already exist? Hot-rodded Priuses are currently claiming 125 mpg, and Tesla Motors' battery-powered Roadster gets 245 miles on a charge. Couldn't the Roadster, which is production-ready and goes from 0 to 60 in less than four seconds, dust everyone?
Not so fast. In addition to getting the equivalent of 100 miles per gallon, vehicles have to contribute less than 200 grams of greenhouse gases to the atmosphere for every mile they drive. This would seem to be a layup for EVs, which have a reputation for emitting only a fine mist of good karma. But electric vehicles aren't as clean as their absent tailpipes might suggest. Because electricity in the US is largely generated from fossil fuels, running a vehicle from the national power grid is far from carbon neutral. So AXP organizers decided that teams would have to account for upstream carbon emissions as well as those from the vehicle itself. Using Argonne National Laboratory data that quantifies the carbon emitted while producing and consuming various fuels, the organizers built a handy spreadsheet that teams can use to figure out whether they meet the 200-gram-per-mile standard. All an entrant has to do is pick the column that corresponds to their vehicle's type of fuel and key in the number of miles it will travel on one unit of that fuel (gallon, kilowatt, et cetera). Then, at the bottom of the document, one of two answers pops up: yes or no: You pass or you don't.
The upshot of considering so-called wells-to-wheels pollution is that a pure EV needs to achieve 133 mpg to pass the AXP emissions test. Even when designers take this into account, optimistic projections can fall prey to reality. For example, while the Roadster passes the spreadsheet test if you use the efficiency figures from the car's white paper, nobody has run the numbers based on actual road tests — until I call Tesla and prompt engineer Andrew Simpson to give it a shot. "I'm plugging in our new numbers right now," he tells me. "And... we don't qualify."
Silence.
The Roadster won't qualify for the X Prize for another reason: The company has no intention to build it in the required numbers. But Tesla does plan to enter its WhiteStar, a four-door sports sedan with a sticker price of $50,000 — about half of what the Roadster costs. Simpson says it's early enough in the new car's development to make adjustments, but he's still not convinced it'll pass. "It's a bigger car than the Roadster," he says, "so I would expect that the efficiency metric would be slightly worse."
