The pressing and unresolved issue of environmental pollution and the increasing concerns on energy supply have led to the production of vehicles with improved fuel economy and reduced emissions, becoming even more necessary. This thesis shows that the gasoline direct injection (GDI) engine will continue to develop in the coming years, becoming a key part of the automotive propulsion market. The work presented has been carried out at CMT - Centro Motores Térmicos, a research centre located in Valencia, fully involved in the development of future combustion engines. The objective pursued is to analyse the behaviour of different kinds of fuel under varying operating conditions, such as temperature and pressure, of either the injected fuel or the combustion chamber.