First, Mazda now prefers the name MX-5 to Miata. More importantly, the Miata, which debuted in 1990, has undergone vast changes for '06. It's 2.5 inches longer in the wheelbase, 1.6 inches longer overall and 1.7 inches wider. It's engine has increased from 1.8 liters and 142 horsepower to 2.0 liters to 170 horsepower.