Mengwasser, J., Macias, J., and Nelson, E., "Piston Cleanliness via Fuel Additive Technology," SAE Int. J. Fuels Lubr. 6(3):935-939, 2013, doi:10.4271/2013-24-0101.
This work compared the piston deposit ratings in an engine when it was run on gasoline with a high concentration of deposit control additive (DCA) versus gasoline with a low concentration of additive. The additives came from different sources and contained detergents with different functional groups. The engine was a Ford V-8 PFI engine, which is used in ASTM D6593, the Sequence VG test. The experimental procedure followed the ASTM protocol, except for the fuel, which was treated with additives.Deposit ratings were better, at 95% confidence, in the tests using a high concentration of additive versus the tests using a low concentration.