Why don’t car makers make cars regulate cars to only go 55 miles per hour? Wouldn’t that help save fuel?

Who would want that car?

because it could be dangerous. imagine you are overtaking someone, and suddenly you hit the limiter at 55mph. what do you do then?

also, nobody would buy a car that was limited to 55mph.

well why dont car manufacturers find alternate fuel sorces? im pretty sure thts a little more reasonable than being forced to go lower than 55, plus those cars would never sell since some speed limits are higher than tht.

save more fuel by limiting speed to 10 MPH

Nobody would buy it. It would be like making a computer screen that saves energy by displaying only an area 2 inches tall and 3 inches wide. Would you use that if you had a choice of a different model?

For many reason, as listed above by the other answerers.

I personally feel that a lot of it has to do with traffic enforcement. Do you know how much money in speeding fines are paid per year per state? I’d estimate millions and millions. These fines go to assist our communities.

not really. they simply would not be ble to sell any. manufacturers respond to market forces. government is slowly making it compulsory to drive slowly and in a small car with fewer journeys by slowly altering our ideas of what is acceptable in transport.
for example within 15 years nearly all new vehicles will have a tracking device fitted so they can see Your Speed .know where u are, travel details etc.
this wil enable insurance and tax to be targeted and thus heavily penalise anybody whom drives too fast too often.
the normal exceptions will occur, police etc and government officials ( famous and rich and so on)specifically Labour lords, Mp’s and large donaters to the political fund.

because there are some people who like to drive faster than 55.

Its not just the speed that uses fuel its in town, up hills, starting stopping etc, my Ford Mondeo does about 25 mpg in town but on a motorway at a steady 75 it will do easy 30

The RPMs needed to accelarateto speed is higher than the RPM needed to cruise.
If your car has a RPM meter,Tachometer, notice the RPM @55 then watch whie driving in stop and go traffic and try to stay below that RPM.

Because it would cause too much chaos on our roads. Trucks, buses and cars would be merrily travelling at 55 mph and I suspect there would be many accidents.