Since first being introduced in 1963, the Porsche 911 has seen its share of updates throughout its lifetime. While many feel the design is a bit long in the tooth, most will agree that the design is what makes it so iconic. Built as a replacement for the Porsche 356, the 911 has literally become synonymous with the Porsche brand. And while the overall design theme has remain largely unchanged, the standard flat-6 engine has remained in place.
Originally it was air-cooled, but Porsche changed it to a water-cooled engine beginning in 1998. While many traditionalists were outraged, it was a significant update that gave the 911 a much needed technical update that made it more competitive against its American rival, the Chevrolet Corvette.