Belt drive system components for smart fortwo 451, showing alternator, poly-V, coolant pump, refrigerant compressor, and stretch belt pulleys.

Engine belt drive diagram with eight numbered callouts identifying pulleys and belt components

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See all Powertrain figures for the Fortwo (451), 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.