An experimental well-mixed thermal reactor system called RAM was devised, tested, and applied to several different size research vehicles. Low emissions were obtained because of the thorough mixing and quick warmup of the system which was aided by flameholders. The study indicates that the RAM concept represents a significant improvement over previously proposed thermal reactor systems.Two versions of RAM were studied. One was operated fuel-rich to minimize NOx at the expense of fuel economy. The other was operated leaner and gave better fuel economy but less NOx control.The best emission results obtained were 3.7 gm/mile CO, 0.08 hydrocarbons, and 0.72 NOx. The fuel economy debit was in the range of 17-22%. Better fuel economy, in the range of 10-17% debit, was obtained at NOx levels of 1.9 gm/mile.Drivability was found to be good. Durability was not tested.