To increase the mileage of Yamaha FZS V3, you should follow some simple tips. Firstly, ensure that you are using the right grade of engine oil for your bike. This can help to reduce friction, which in turn increases the mileage. Secondly, keep your bike in a good condition by regularly servicing it. This will help to reduce fuel consumption and get the maximum out of your engine. Finally, ride your bike at a steady speed. This will help to improve your overall mileage.