Piston Ring, Engine

Piston Compression Ring Groove Clearance:
Production Top 0.030-0.070 mm (0.0012-0.0027 inch)
Production 2nd 0.040-0.080 mm (0.0015-0.003 inch)
Service Limit Top 0.030-0.090 mm (0.0012-0.0035 inch)
Service Limit 2nd 0.040-0.100 mm (0.0015-0.0040 inch)
Piston Compression Ring Gap: [1]
Production Top 0.30-0.58 mm (0.012-0.022 inch)
Production 2nd 0.51-0.71 mm (0.020-0.028 inch)
Service Top 0.30-0.85 mm (0.012-0.025 inch)
Service 2nd 0.46-0.90 mm (0.016-0.035 inch)
Piston Oil Ring Groove Clearance:
Production 0.051-0.17 mm (0.002-0.006 inch)
Service 0.051-0.195 mm (0.002-0.0078 inch)
Piston Oil Ring Gap: [1]
Production 0.25-0.76 mm (0.010-0.030 inch)
Service 0.25-0.785 mm (0.010-0.030 inch)

[1] End gaps measured in cylinder bore.