Why current cars can’t exceed more than 300 Miles per hour?

why cars cant exceed 300 mph?چرا خودروهای کنونی به سرعت بیشتر از ۳۰۰ مایل بر ساعت نمی‌رسند؟

Mankind is always trying to speed up the process of doing his or her works, for example we can point to many inventions such as steam engines, in the past we used horses to pull wagons and it was very slow, but today we are using engines which can out-work animals in very large quantities.

Scientists and inventors tried to push speed limits of the car from the day which the automobiles were invented, if we read the maximum speed of first cars and compare them to our current cars, huge differences were made through this timeline, and very now and then a news from car industry will shock us all, who can believe a 1000 horsepower road car?!

Currently, we don’t have a car which can exceed more than 300 miles per hour (about 480 kilometer per hour or 134 meter per second) this fact has so many reasons, in this article we are trying to explain these reasons, it’s worth to mention that this thing is impossible with current technology and in future we can see this limitations will push further back.

There are different elements which affect moving object and to reach higher speeds we should conquer them, these elemets are: air friction, aerodynamic drag and tyres rolling resistence.

For example, a specific car which weights 1900 kilogram, needs 1476 horsepower or 1.1 megawats energy to overcome aerodynamic drag force in 300 MPH, this number came from a formula which has effective elements of  speed, density of air, temperature and drag coefficient of car.

As we mentioned, it needs about 37.26 kilowat or about 50 horsepower energy to overcome rolling resistance, these numbers also came from a formula with force and velocity as key elements.

To this day mankind could’nt make a machine which can convert 100% potential energy to moving energy and not a single car can transfer all the power generated from engine to wheels and we always will have some wasted engery. For example in the case we mentioned earlier, we will need 1526 horsepower to exceed over 300 MPH, now if we presume our machine would waste 15% of generated power through transmission, out 1900 kilogeram cars, should generate 1.34 megawatt or 1800 horsepower to exceed the 300 MPH speed barrier.

Also in these conditions, cooling systems and tyres are very important, wheels should be connected to the road’s surface and have absolutely no vibration, as we said, no car was ever built which is capable of breaking this barrier but we will see one soon enough.