Fuel additives are used to improve engine performance in a variety of ways.
DMCHA and DMAPA (see Personal Care) are used for gasoline and motor oil additives.
MMA and chlorobenzene are reacted with copper as a catalyst to make n-methylaniline for aviation fuel. DMA hydrochloride is also used as an additive in aviation fuel as an antiknock compound.
MMA nitrate is a freezing point depressant in jet engines using ammonium nitrate-urea fuels. Mixtures of MMA, DMA, and TMA in water have been tested as coolants in some high-speed engines.