sentences:  Rocket cars are capable of very high speeds, and at one time held the land speed record (now held by a jet car).Rocket cars differ from jet-powered cars in that they carry both fuel and oxidizer on board, eliminating the need for an air inlet and compressor which add weight and increase drag.Rocket cars run their engines for relatively short periods of time, usually less than 20 seconds, but the acceleration levels that rocket cars can reach due to their high thrust-to-weight ratio are very high and high speeds are fairly easily achieved.