A Miller cycle combustion engine capable of operating on multiple fuel
types, and a method of operating the engine, is provided. The engine
includes a fuel type determiner to determine the fuel type, and a
compression adjustor to adjust the compression of a first cylinder of the
engine to match the requirement of the determined fuel type. The
compression adjustor is a variable valve timing system that provides a
maximum compression when a fuel type requiring maximum compression is
determined, and that advances or retards the opening of the intake valve
to provide lower compression when a fuel type requiring lower compression
is determined.