Quic - Rear
- Quick-detachable coupling
- Quick-release valve
- Quiescent chamber
- Quiescent combustion
- Race-course
- Racing car
- Rack-and-pinion steering
- Radar surveillance
- Radial engine
- Radial runout
- Radial tyre (radial-ply tyre)
- Radiating fin
- Radiator
- Radiator blind
- Radiator cap
- Radiator cleaner (radiator flush)
- Radiator core
- Radiator grille
- Radiator shutter
