System and method for combustion engines

The invention relates to a method for improving combustion in a combustion chamber of a combustion engine. The method comprises the first step of receiving a measured air-to-fuel ratio value. Further, the method comprises the step of receiving at least one estimated air-to-fuel ratio value. The air-to-fuel ratio estimate is generated in dependence of a predetermined fuel deposit factor. Furthermore, the method comprises the step of establishing a fuel volatility value in dependence of said measured air-to-fuel ratio value and said air-to-fuel ratio estimate. Finally the method comprises the step of controlling combustion in dependence of said fuel volatility value.