system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why are cars made to be able to go speeds well above any speed limit, when they aren't made for reaching?
gpt
A lot of road cars are designed to be efficient. They want to be working as little as possible at the speeds they are most likely to go at.

An engine that can only get a car to 60mph/100km/h will be working as hard as possible all the time if you were on an open highway. This would wear the engine down and lead to more faults as the parts are pushed to their absolute limit.

An engine that can get the vehicle to 140mph/225km/h will effectively be working way less when keeping at 60/100. This results in less fuel usage, less wear and tear, less part failure and less hassle for the consumer.