Influence of Fuel Properties on Lubricant Oxidative Stability:Part 1 - Engine Tests

Lubricant samples were aged on a SI bench engine that was run using ten different gasoline fuels. For each gasoline tested, the oxidative stability of the lubricant and the extent of engine wear was assessed in terms of a number of different parameters.

Surprisingly, it was found that fuels containing higher levels of olefin (whether C8 olefin, or a C5/C6 olefin blend, or a catalytically cracked refinery stream) performed directionally better than a reference gasoline with low levels of aromatics and olefins.

Fuels with a higher final boiling point and higher aromatic content, appeared to be associated with enhanced levels of sludge formation than the reference gasoline, but did not give rise to enhanced engine wear.