why do cars have speed-o-meters up to 180 although we're only allowed to drive up to 180?

Question

emergencies might be an acceptable answer, but then why the large gap between the maximum speed and the speed limit?

oops, i meant why do cars have speedometers up to 220 when we're only allowed to drive up to 180. ;P

Answer 1

The gap in the speed depends on how the car was calibrated for accurate speed. with the newer cars, they commonly no longer use cables to track your speed. Most now are completely electronic and work of the relative speed of the wheels and the transmission. The gages are set simply for a guide so the driver knows how fast they are traveling. You also need to consider that if you do exceed the limits of a speedometer that is only rated for 85, your mileage on the odomiter will no longer be accurate. Having a higher range insures a more accurate mileage reading. Most newer cars are unable to achieve the top speed listed on the speedo do to drag, imposed governs, and rev limiters. It's just a device to let us humans know how fast we are going. They really don't mean anything other then that. Look back in the 80's and attempt to find a Speedo that was higher then 85. only in the sports cars do you see the speedo go higher then 85.

Answer 2

Because there are places where you're actually allowed to go that fast (some segments of the Autobahn, etc).

There's also the marketing appeal of "this car can do 270 km/h, otherwise why would we make the speedometer reach 280 km/h".