While browsing your local CL, you see 2 Hupmobiles for sale - one with 500hp V36 and one with a 400hp V36. I can read your mind to see that you would take the 500hp car.
What you didn’t know, is that when both engines were placed on a dyno, their power curves looked like this:
Yeah, the orange Hup makes a maximum of 500 hp at the top of the tach, but it’s a complete dog until then. Meanwhile, the 400hp Hup has 400hp almost everywhere.
If you pick the orange Hup to have a better chance of smoking a Subaru Justy at every stoplight, prepare to be disappointed.
But every engine must be paired with a suitable transmission. To make the most of its short-lived >450hp, the proper transmission for the orange hup would need very close ratios to keep the engine in that 5500-6000 range. Even then, it would still be sluggish off the line. Meanwhile, the orange Hup would be well off with wider ratios.
Then there’s the factors of torque, and gearing...
To the engineers: Is there anything that I missed? Specifically, what’s the role of torque here? Besides that it combines with RPM to make HP.