Stiffer, lighter, and more power was the plan for the 1991 to 1994 Porsche 911 (964) Carrera RS. Porsche hit its mark perfectly with the RS. To call these cars, track-focused is an understatement. The RS remains some of the most collectible Porsches today for a good reason. The unibody of the RS was seam welded for added rigidity. The weight was reduced by 286 lbs, giving the car an aluminum hood, thinner glass, lighter magnesium wheels, special racing seats, new door cards and the removal of the air conditioning. Comfort was not the priority. In addition, ten horsepower was added to its balanced 3.6L flat-six engine, which delivered power to the rear wheels via a Getrag G50 transmission. Porsche also made an RS touring model with slightly more accouterments.