It may be impossible to create a perfectly efficient engine, so our ideal of a real perfect engine won’t be perfectly efficient.
Our ideal is presumably an efficiency expressed as a number. Any efficiency less than 1 can be reached. Any efficiency less than 1 will have a higher efficiency that is still less than 1, and can be reached. Therefore no efficiency less than 1 can be our ideal.
Our ideal is presumably an efficiency expressed as a number. Any efficiency less than 1 can be reached. Any efficiency less than 1 will have a higher efficiency that is still less than 1, and can be reached. Therefore no efficiency less than 1 can be our ideal.