Take for example the 4 cylinder Mercedes CLA-45, it has the most powerful production 4 cylinder engine in the world rated at 375 HP and 350 Ib-ft. Then look at V12 engines early on and you can see that they produced less then half that. It would take 50 years to start to reach modern day engine output numbers but even then you needed big displacement V8’s or crazy prototype race car engines.
So my question is: How come your brand new Toyota Corolla is much more powerful than cars as they were starting out, despite not having the same regulations as we do today (noise, pollution, etc)? Is this just due to better efficiency overall?
Edit and TLDR: How have engines been made more efficient?