Tall, Skinny tires: Newest Green-Car Efficiency Trend
I noticed that NHTSA is tasked with writing new regulations for specifying the rolling resistance of tires as well as performance metrics (so that people don't sacrifice too much safety for efficiency sake.) They also seem deeply concerned with replacement tires (non-OEM) being significantly less fuel efficient than OEM tires. This comes from OEM tires being a factor in CAFE and replacement tires are not. That should change soon.