The NA (1989-1997) is the original Miata and still the purest expression of the formula: a sub-2,300 lb roadster with pop-up headlights, a naturally aspirated four, and rear-wheel drive through a short-throw five-speed.
Two engine families ran across the NA's life, both timing-belt-driven and both non-interference, so a snapped belt strands you but does not bend valves.
- 1.6L B6ZE (1989-1993): Roughly 116 hp. Rev-happy and light over the nose; the enthusiast favorite for feel, though down on torque. Early cars also have a smaller-diameter flywheel and thinner axles.
- 1.8L BP (1994-1997): Roughly 128 hp (1994-1995) rising to about 133 hp for the OBD-II 1996-1997 cars. More torque and stronger internals; 1994-up also gained a stiffer chassis and, on many cars, a Torsen limited-slip differential.
- Short-nose crank: Early 1.8 engines (1994 to mid-1995) use a short crank nose whose keyway can shear if the crank bolt loosens, destroying timing. Confirm the pulley is tight and the bolt has been re-torqued or upgraded.
- Chassis: Double-wishbone all around, near 50/50 balance. Mazda's PPF powerplant frame ties engine to diff for crisp response.
Buy on condition, not mileage. Rust in the frame rails, rocker panels, and rear subframe mounts kills more NAs than any mechanical fault. A rust-free 1.8 with a Torsen diff is the sweet spot; a clean 1.6 is the connoisseur's choice.