How do we improve the internal combustion engine?

Add more fasts

Multiple sequential engines

Add more braps per minute

Make it a triangle, where each side completes intake, compression/combustion, and exhaust all in one rotation. Then add turbos.

I agree. With todays composite materials, efficient electronics and computer simulations cars could weight a fraction of what they do today.

LOL

anti-gravity hovercars, we have the tech but the military-industrial complex won't release it for the next 100 years at least

move on to better things

by deleting and switching to rotary :)

Improve power? No idea
Improve efficiency? Different fuels

Rotary is combustion.