When it comes to gearing, everything is about compromise. Shorter gears give rip snorting acceleration, while taller gears allow for better fuel economy and a higher top speed. But, changing individual ratios in a gearbox is anything but simple. In addition, changing an entire gearbox will prove to be quite expensive.
However, if you want more top speed or better acceleration, there is an easier solution: change the final drive ratio. Those of you who think that the gears within the transmission are the only gears are utterly wrong. There is a gear in the rear differential as well which puts the power to the ground. It’s known as the final drive.
If you fit a shorter final drive you will get better acceleration and you choose the taller one, you’ll increase your top speed. Be that as it may, itis important to set your priorities straight. If you choose to increase acceleration you’ll have poor fuel economy and it will get nosier.