Patent ID: 7887695

Claim:
A method for operating a homogenous charge compression engine having a piston and cylinder for mechanical compression comprising: supplying a hydrocarbon feedstock wherein said fuel is characterized by having all of the following properties: (1) a 95% ASTM D 86 boiling point of about 35° C. to about 350° C.; (2) a cetane number in the range of about 2-20; (3) an octane number in the range of about 63-110; (4) an elevated pressure autoignition temperature (EPAIT) of about 400° C. to about 800° C.; and wherein essentially all of said fuel is further characterized as capable of converting to a vapor phase before combustion onset in said homogeneous charge compression engine and said fuel has an ignition delay such that the onset of combustion is achieved by said fuel after said piston has exceeded the point of maximum mechanical compression.