One would think that true based on the thermodynamic first principles of the Otto and Diesel cycles, but you are actually incorrect due to a number of innovations such as fuel injection, EFI, direct injection, intake design, CFD analysis, materials advances which allow higher temperature and more efficient combustion, and turbocharging.[1] In addition, I happen to work on automotive and small engines, and can assure you that engine reliability has dramatically increased over the whole span of their existence, and every interval thereof.

[1] http://www.achatespower.com/pdf/opposed_piston_renaissance.p...