Tele - Thro
- Telescopic aerial
- Telescopic fork
- Telescopic jack
- Telescopic shock absorber
- Telescopic steering column
- Telescoping
- Temperature gauge
- Temperature map
- Tension spring
- Terminal
- Test bench (testing stand)
- Test car
- Test cycle
- Test driver
- Test run
- Testing track (test track)
- Theft-proof
- Theoretical power
- Thermal balance
- Thermal efficiency
- Thermal loading
- Thermal reactor
- Thermflow piston
- Thermo-syphon water cooling
- Thermostat valve
- Thermostatic interrupter
- Thin-wall bearing
- Threaded plug
- Three-axle-truck-trailer
- Three-bearing cranckshaft
- Three-quarter floating axle
- Three-way cock
- Three-way converter
- Three-way tipper (three-way dump truck)
- Three-wheeler