Engine piston ring identification, compression ring, and cylinder barrel cross-section diagram with measurement procedure using feeler gauge.

Technical cross-section diagram showing piston rings in cylinder barrel with numbered callouts and feeler gauge measurement tool.

View full-size image ↗

See all Powertrain figures for the Fortwo (450), or browse the full figure library. Part numbers and callouts are community-sourced and cross-referenced against the manuals — confirm with your VIN before ordering.