Actually just the opposite is true. Modern engines often get 2+ hp per cubic inch straight from the factory with amazing mileage performance. Impressive that a 2.5 l engine can deliver 300 horses. You are right about cost but it is worth it. I used to have Camaro z28’s several in a row. Factory 185 hp with 12 mpg, now I have trucks with almost twice the weight that come from the factory with 285 hp and get 17mpg.
” You are right about cost but it is worth it”
Remember that when you discover your new car shuts its motor off at every traffic light and no its not worth it. I’d rather pay 30-40% less and go back to the days when cars were designed for style, comfort and performance. Instead the companies have to jigger their car lines to meet cafe standards and the price for that is less choice and much higher costs.
You are right, of course. But just think if the CAFE were relaxed a bit. My 435hp Mustang might get 500...
But the optimization is mostly accomplished by computer controls. I hate that I’m driving a server, and if some little sensor malfunctions, it could literally shut off my engine for no reason... AND it will COST me to get it fixed, when the car would run just fine without it. (When my backup camera goes out, I just turn and look behind me - remember that?)