Stanadyne Performance Formula Diesel Fuel Additive - Pack of 4 Pint Bottles - Part # 38565 Restores/Increase Horsepower  detergents clean deposits in the injection system Reduces Fuel Consumptiontests show an average of 4% improvement in MPG and gains up to 9.6% Cetane Improver  improves combustion resulting in better engine starting, running & reduced noise Reduces Wear  lubricity improvers restore lubricity to ultra low sulfur diesel fuels Reduces Emissions  reduces Smoke and Particulates