Abstract: A speed control governor for regulating the maximum speed of internal-combustion vehicle engines, particularly compression-ignition engines for heavy goods vehicles, the latter having a gear shift mechanism and a fuel supply pump provided with a spindle which regulates the supply of fuel and is connected to a regulating lever which is pivotable upon movement of the vehicle accelerator pedal. An end abutment is provided to limit the maximum movement of the regulating lever to thereby define the angular end position of the fuel pump regulating spindle, and adjusting means are provided which are automatically operated when top gear is selected, the effect being that the angular end position of the regulating spindle of the fuel pump is adjusted from a maximum fuel value to a smaller fuel value when the regulating lever engages the end abutment.