Car companies can't make changes fast enough to suit car buyers. When gasoline made its recent price jump to $4 per gallon, consumers immediately began looking for better mileage, no surprise there, but what can car makers do? Low rolling resistance tires are getting a lot more attention because an existing design can have the tires changed and the suspension re-tuned much faster than waiting for the next new model to hit the roads.
There are trade offs when low rolling resistance tires are used, one of the first is braking distances increase as the rubber grips less. The increased distance can be appreciable and it's one more indication there aren't any magic bullets that can dramatically increase mileage overnight.
Many things influence rolling resistance, the tire's physical construction, for instance, thinner sidewalls and less tread depth, plus the mixture of natural rubber and synthetic materials and fillers is altered. Juggling all of these variables is difficult when your aim is to improve one factor such as rolling resistance while not sacrificing in others such as tire life, wet weather grip or overall handling. Just as light weight cars are smaller and drivers need to get used to that, low rolling resistance tires include differences of their own.
Link: Automotive News (subscription required)