| To sell them to people who want to go fast or want to have the possibility to go fast, but it also used to be for technical reasons. Most cars have a gaz engine and the efficiency of a gaz engine is not linear. To simplify, an engine often has its best efficiency around 2000rpm and can rotate as fast as 6500rpm but it will then waste a lot of energy, mostly in heat. You want the engine to operate at its best efficiency when you drive normally. So you design the gearbox accordingly, to get 2000rpm at 130km/h for example. But the engine can rotate faster, and therefore you can drive faster than the speed limit. You can limit how fast the engines rotates, most engines do have a limit around 6500rpm, but if you limit the rotation speed, the cars will lack a lot of power. The power is the torque of the engine (how strong it can rotate) multiplied by the rotation speed. So limiting the rotation speed is quite a problem. Many people prefer to buy powerful cars. They don't even know about the torque. You could limit how fast the engine rotates once you reach the speed limit, but for a long time this kind of technology was quite complex and expensive. Nowadays, since maybe 25 years, it's totally fine and cheap to do so. Some German brands put an electronic at 250km/h on their fast cars for example. With electric cars it's another story and while most don't go very fast, mine goes up to 150km/h for example, some are fast only to sell them to people who want fast cars. Today we could definitely put a limit at the legal speed limit, based on GPS and map data and for example, but many people would complain and some would buy a car without the limit. I think the only solution is to force all the constructors to do implement a speed limit at the same time. |