The typical maximum speed range for heavy-duty trucks is between 80 and 100 km/h. According to Chinese traffic regulations, the speed limit for large trucks on highways is 100 km/h, but the specific upper limit varies depending on the type of heavy-duty truck. For example, a lightly loaded heavy-duty truck might reach a maximum speed of 100 km/h, while a heavily loaded one might be limited to 90 km/h or 80 km/h.
In addition, there is a very special heavy-duty truck built by the American tuning company Les Shockley specifically for drag racing. This truck is equipped with three Pratt & Whitney J3448 jet engines, achieving an astonishing top speed of 605 km/h. However, this specially modified vehicle is quite rare and cannot be used as a representative of the speed of ordinary heavy-duty trucks.
To calculate the speed of a heavy-duty truck, you can use the formula: 0.19 * n / transmission ratio / rear axle ratio. For example, when calculating the vehicle speed at 1200 or 1400 RPM, simply substitute 'n' as a variable into the formula.
It must be noted that, according to national law, the maximum speed of heavy vehicles is limited to 90 km/h or lower. This means that even if the calculated speed is higher, the vehicle cannot exceed this speed because when the speed reaches 90 km/h, the engine stops increasing the amount of fuel or gas injected, the RPM stops rising, and the vehicle speed cannot be increased further.
