One way to boost a car's mileage is to increase tire pressures, which reduces rolling resistance.
But increased tire pressure means a harsher ride on uneven surfaces. Cornering ability suffers as well.Now the Goodyear Tire & Rubber Co. and Lotus Engineering of England are collaborating on a "smart" tire that would inflate and deflate in response to road conditions.
The tires would run at a fuel-saving 45 pounds per square inch on smooth highways, deflate to 25 psi on a surface filled with potholes and then pump back up to 45 psi when the road smoothed out again.
The system, which Goodyear calls "active air," would use silicon sensors embedded in each tire.
The would monitor pressure, temperature and motion and transmit data to a computer processor in the car, which would in turn regulate the tire pressure.
A small air compressor in the car would reinflate the tires as necessary.
Smart tires would primarily be used in with active suspension, a system developed by Lotus that uses computer-controlled, high-pressure hydraulic cylinders.
Goodyear and Lotus, a unit of General Motors Corp., expect active suspension to reach the market in some cars in the 1992 model year, with smart tires following a year or two later.