#30 – Introduction Of The Catalytic Converter
The 1975 Corvette was the first model to include the federally mandated catalytic converter and only took unleaded gas. The converter is an exhaust emission control that transforms gasses into less-toxic pollutants. As a result of these additions, the 1975 Corvette could only reach 165 hp (the lowest speed in the C3 generation) unless customers purchased an L-82 engine. (Not all vehicles featured in the image above are 1975.)