The spark plug gap for a 1988 Ford Ranger depends on the engine. You
must check your owner's manual for the precise specification. The manual will list the correct gap for your specific engine (e.g., 2.3L, 2.9L, or 4.0L).
Failing that, a reliable auto parts store can look up the correct gap based on your vehicle's VIN. Don't guess – an incorrect gap can lead to misfires and engine damage.