A 3.55 axle ratio is a gear ratio used in automotive applications. It is the number of times the driveshaft turns for one revolution of the wheels. A lower number like 3.55 means that the driveshaft turns less for one revolution of the wheels, while a higher number like 4.10 would mean that the driveshaft turns more. This affects how your vehicle accelerates, as well as its top speed and fuel economy.
In general, a lower axle ratio like 3.55 will result in better acceleration but worse fuel economy, while a higher axle ratio like 4.10 will result in worse acceleration but better fuel economy. The best way to choose an axle ratio is to strike a balance between these two factors based on your driving needs and habits