Without knowing the technology and principals used then yes it is hard to believe. Until then I am open minded. Especially as manufacturers with millions or billions to spend on research haven't utilised the technology. Stratified combustion is the nearest thing I can think of but this isn't obviously the same.

However if you can utilise more of the energy stored in the fuel rather than turn it into heat and noise as we currently do with internal combustion engines then that energy conversion must become some other form of energy. If the result is less heat but the noise levels don't increase then surely that energy must become kinetic energy?