Motor gasoline composition

Abstract

An embodiment of the present invention provides a motor gasoline composition which controls formation of deposits in air intake systems and combustion chambers (particularly, the latter) of gasoline engines, keeping them clean without using a detergent. The motor gasoline composition contains saturated hydrocarbons, aromatic hydrocarbons having a carbon number of 7 or less, and aromatic hydrocarbons having a carbon number of 8 or more, the composition having a combustion chamber deposit formation controlling index satisfying the following relationship: Combustion chamber deposit formation controlling index A/B>6 wherein, A is a total content (wt. %) of saturated hydrocarbons of unspecified carbon number and aromatic hydrocarbons having a carbon number of 7 or less, and B is a total content (wt. %) of aromatic hydrocarbons having a carbon number of 8 or more.

What is claimed is:  
     
         1 . A motor gasoline composition containing saturated hydrocarbons, aromatic hydrocarbons having a carbon number of 7 or less, and aromatic hydrocarbons having a carbon number of 8 or more, said composition having a combustion chamber deposit formation controlling index satisfying the following relationship: 
 Combustion chamber deposit formation controlling index=A/B>6 wherein, A is a total content (wt. %) of saturated hydrocarbons of unspecified carbon number and aromatic hydrocarbons having a carbon number of 7 or less, and B is a total content (wt. %) of aromatic hydrocarbons having a carbon number of 8 or more.    
     
     
         2 . A method of controlling combustion chamber deposits by providing to an internal combustion engine an effective deposit controlling amount of the composition of claim  1 .