Question

is it possible to create a highly efficient engine which is 1oo% efficiency?

Answer 1

No, it is not

Answer 2

You only want kinetic energy, but you will also get friction energy always.

Answer 3

obviously not with internal combustion engine

Answer 4

There is more to inefficiency than just wasted inputs. It is not possible for any mechanism to convert heat to work with 100% efficiency at any finite temperature. What type of engine and what fuel are used are completely irrelevant, it just cannot be done via the laws of thermodynamics. There is always some energy lost as heat, and that cannot be recovered.

Answer 5

Seriously though, the laws say it can not be done in theory, but one can be produced with a high level of efficiency. Maybe not 100%. He is correct.