Technical reference
Segments
What a vehicle type is, what it carries, and where it earns its keep — from tipper to reefer, city bus to coach.
Aerodynamic cabs and the EU length rules
Axle ratios and final drive: single reduction, hub reduction and portal
Bus Doors and Emergency Exits Under UN Regulation 107
Bus Fire Safety Under R107 and R118: Two Separate Regimes
UN R66 Bus Rollover Strength, and the Classes Left Out
Bus Seat Belts: Which Classes Must Have Them, and Who Must Wear Them
Kingpin and fifth wheel: what makes a tractor and a semi-trailer compatible
Retarders and engine braking: what UN R13 asks a heavy vehicle to prove
Semi-trailer dimensions: the rules behind the 13.6-metre deck
Trailer types explained: what each semi-trailer body carries
Bus Classes Under UN R107: Class I, II, III, A and B
How to Read an Otokar Coach Specification Sheet
Automated manual transmissions in heavy trucks
Axle configurations explained: 4x2, 6x2, 6x4 and 8x4
kW, hp and Nm: how to read a truck's power figures
Truck cabs: classes, heights and sleeper types
Turbocompound engines: what they are and when they pay