When you warm up your car, only one in five injected gas molecules actually combusts and delivers power. The rest puddle up and evaporate, resulting in excessive emissions of hydrocarbons. The solution-a special fuel designed to burn efficiently during warmup-was developed years ago, but car manufacturers decided it wasn't practical to expect consumers to keep two tanks filled with different fuels. Now, engineers at the University of Texas and Ford Motor have devised a way to distill the special "warmup" gas from standard gasoline within the engine itself. The system, which could reduce auto emissions by over 50 percent and carcinogenic toxins by 80 percent, should be available within four years. -E. Brown