A system and method for controlling the viscosity of liquid fuel delivered from a fuel tank to the fuel injectors of an internal combustion engine. A viscosity sensor is placed in the fuel line, or in a bypass fuel line, in close proximity downstream the fuel injectors. A heat exchanger is placed on the fuel line downstream the sensor. The sensor is a rotating cylinder having a nominal rotation velocity, and is configured to rotate such that the nominal rotation velocity increases or decreases in response to fuel viscosity. The sensor delivers a measurement signal to a control unit, which performs a closed loop algorithm to adjust the heat provided by the heat exchanger until the measured rotation matches a target rotation.
Terrence F. Alger II