Engine Compression

WARNING: This page is about a different car, the 1994 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

Warm engine to normal operating temperature. Remove all spark plugs. Disconnect ignition coil primary wire connector.
On all models, hold throttle plate fully open. Crank engine, and note compression pressure.

COMPRESSION RATIO

Application	Specification
Miata	9.0:1

COMPRESSION SPECIFICATIONS

Application

Minimum psi (kg/cm² ) @ RPM

Standard psi (kg/cm² ) @ RPM

Miata ⁽¹⁾

128 (9.0) @ 300

182 (12.8) @ 300

⁽¹⁾	Difference between cylinders should not be more than 28 psi (2.0 kg/cm² ).