HILTON HEAD, S.C.—The advent of hybrid-engine automobiles, those incorporating two power sources, could be just what the run-flat tire market needs to jump-start sales. Toyota Motor Corp. and Honda Motor Co. both will have hybrid vehicles in the U.S. within the next year, said Brett Smith, senior research associate at the University of Michigan's Office for the Study of Automotive Transportation. General Motors Corp., Ford Motor Co., Mitsubishi Motors Corp. and Nissan Motor Co. Ltd. likely will follow with their own versions in 2000.
These vehicles require significant reductions in weight, providing an opportunity for run-flats, which would allow for the elimination of the spare tire, he said.
``The need to reduce weight on hybrid vehicles is so huge that run-flats make very obvious sense when you make the selection of tires for those vehicles,'' Mr. Smith said.
Hybrids are vehicles with two power sources, Mr. Smith said in an interview during the recent Clemson Tire Conference. For example, a hybrid vehicle might have an internal combustion engine as well as an alternative-fuel power source such as an electric motor.
The gas engine could be used to create energy which is stored in a battery for powering an electric motor that drives the wheels.
Another hybrid format might involve the two engines kicking in at different speeds. The gas engine would run the vehicle at speeds over 30 mph, while the electric engine would take over at slower speeds.
The federal government's desire to boost vehicle fuel efficiency and reduce emissions also could encourage run-flat tire use, Mr. Smith said.
A key way of curbing emissions is to pare vehicle mass, allowing use of a smaller engine, he said. And one way of decreasing mass, besides using lighter-weight materials, is to get rid of the spare tire.
``Although we don't see gas prices driving (demand for reduced-mass vehicles) in the near future, the government's desire to reduce emissions through CAFE (corporate average fuel economy requirements) or through emissions regulations offers the opportunity for run-flats through wider use of internal combustion engines,'' Mr. Smith said.
The question is when and if the government will take action.
``We keep hearing the government's going to raise gas prices—that they're going to do something to drive the consumer to more fuel-efficient vehicles,'' he said. ``That hasn't happened since the 1970s.''
Instead, people began driving trucks, he said.
Still, he sees much development in the area of alternative fuels, with some technologies offering an opportunity to increase vehicle mileage significantly.
``Once you start getting 70 mpg from a hybrid, internal-combustion-engine vehicles will probably have to start getting lighter to compete,'' he said. ``It's going to be driven in a lot of ways by government regulations and the customer reaction to them.
``If the hybrids become accepted through government regulations or technological advances, a key factor will still be the reduction of mass,'' Mr. Smith said. ``That could provide a real opportunity for run-flats.''