Piston Ring, Engine

Piston Ring End Gap - First Compression Ring - Production 0.25-0.40 mm (0.010-0.016 in)
Piston Ring End Gap - Second Compression Ring - Production 0.38-0.58 mm (0.015-0.023 in)
Piston Ring End Gap - Oil Control Ring - Production 0.25-0.76 mm (0.010-0.029 in)
Piston Ring End Gap - First Compression Ring - Service 0.25-0.50 mm (0.010-0.020 in)
Piston Ring End Gap - Second Compression Ring - Service 0.38-0.80 mm (0.015-0.031 in)
Piston Ring End Gap - Oil Control Ring - Service 0.005-0.090 mm (0.0002-0.0035 in)

Piston Ring to Groove Clearance - First Compression Ring - Production 0.030-0.070 mm (0.0012-0.0027 in)
Piston Ring to Groove Clearance - Second Compression Ring - Production 0.076-0.280 mm (0.0030-0.0110 in)
Piston Ring to Groove Clearance - Oil Control Ring - Production 0.046-0.196 mm (0.0018-0.0077 in)
Piston Ring to Groove Clearance - First Compression Ring - Service 0.030-0.085 mm (0.0012-0.0033 in)
Piston Ring to Groove Clearance - Second Compression Ring - Service 0.030-0.085 mm (0.0012-0.0033 in)
Piston Ring to Groove Clearance - Oil Control Ring - Service 0.076-0.200 mm (0.0030-0.0079 in)