Now that the blogosphere is assuming “D” is a Model S with dual-motor all wheel drive, it’s time to revisit an important product claim by Tesla. The dual-motor all wheel drive system is “efficiency neutral,” so it’s no more energy-hungry than rear drive. This is a slap in the puss of gas-engined cars, whose MPG always suffers with AWD. It’s just one more way in which Tesla seems exempt from the laws of physics.
Wouldn’t it be nice to hear Tesla make this claim, instead of reading about it? Seems nobody can find a link. Well, here’s the link. Skip to 45:55 to hear CEO Musk and CTO Straubel touch on Tesla’s AWD system and its efficiency. If you’re too lazy to click the link, here’s a transcript of the AWD comments:
Musk: “The challenge with the X is not the all wheel drive but rather the fact that the car will have a greater frontal area and probably a slightly worse drag coefficient, so its energy consumption will probably be about ten percent greater per kilometer than the S, just because it’s a bigger car. But it’s unrelated to the powertrain.”
JB: “Certainly the typical experience with all wheel drive versions of vehicles is that, you know, the efficiency will be worse. That’s kind of intuitive because you have more parts moving, more weight. We’ve worked really hard to not have that same effect, and we’ve found some clever ways in the architecture of how we do the dual motor all wheel drive, by literally using two different electric motors in the car, not just a mechanical linkage between the front and rear, so that we essentially can have that be an efficiency-neutral option. So that’s a pretty big breakthrough in all wheel drive. I think that’s the only time the all wheel drive version of any car has had basically a flat efficiency trade-off. So you can have the function without any penalty.”
Three cheers for neutrality.