The Relationship Between Gasoline Additive Thermal Stability and Combustion Chamber Deposits

The relationship between thermal stability of gasoline additives and their effect on engine combustion chamber deposits (CCDs) has been explored using a wide range of candidate gasoline additive chemistries. Although a weak correlation may be observed between thermal stability and total CCDs, the data scatter is far too great to permit the relative CCD performance of additives to be predicted from thermogravimetric analysis (TGA) properties alone. It is concluded that TGA alone is too simple a measure to reflect the true complexity of deposit formation in a combustion chamber and that correlations with CCDs degrade further when TGAs are determined from UWG samples extracted from additivated gasolines.