How The size of a car affect the speed?

Answer 1

Simply put, the size of the car makes quite a big difference.

Put it this way, a Suzuki GSX-R 1300 Hayabusa motorcycle is capable of reaching a top speed of 208 mph, however it accelerates to that speed very quickly. Now the Hyabusa has 156 hp from the factory. The weight of a Hyabusa is around 500 pounds depending on the year. It travels from 0-180 mph in 15.6 seconds.

Now a Lamborghini Gallardo LP560 has a top speed of 210 mph, which is about the same as the comparison, it takes the Gallardo about 30 seconds to hit 180 mph from a standstill. It weighs about 3,500 pounds.

This doesn't include simple dimensions (height, weight, length), and drag coefficients, and plenty of other things that factor into it.

However, gear ratios and all that sort of thing have a lot to do with how fast a car will go or how fast a car will accelerate, but to answer the question, a 2 door sports car with the same engine as a 4 door luxury sedan will outperform the 4 door in just about every category performance wise. It's simple physics.