When you think engine size in a gas-operated motor vehicle, you think number of pistons. Well, Mazda doesn't. The only OE to still use the rotary engine, unlike a conventional engine with dozens of moving parts, the rotary only has, coincidentally, three and carries a much smaller displacement. Rotary 101 aside, the sporty RX-3 was campaigned in the Japanese Grand Prix of 1972, where it was the only car to topple the previously undefeated GT-R.