Abstract: A fuel feed system for an internal combustion engine, of the type in which a fuel line from a fuel tank contains a fuel feed pump for supplying fuel under pressure to at least one fuel injection pump operating to inject fuel into the internal combustion engine, the injection pump having an outlet for excess fuel connected to a return line leading back to the fuel tank. In this return line there are two branches, one of them containing a heater for heating fuel flowing in that branch of the return line; a solenoid valve selectively energized in dependence on the fuel temperature in the tank causes the fuel to flow in the heater-containing branch of the return line when the fuel temperature in the tank is below a selected minimum. Filters in the fuel feed line are provided with heaters energized in dependence on the fuel temperature in the fuel feed line immediately downstream of the filter.