what is tire rolling resistance and how much it help

[malek]

want to know what is tire rolling resistance and how much in fuel saving it will help me. my friend advise go with class a or b rated tire, but I want to know how big or small fuel saving difference I can make from class a to class z? thanks all

[ethan]

Rolling resistance means for how long the tires can freely rotate once you leave the gas pedal. Smoother straight line highway thread have least rolling resistance and roll the car for long once you lift off the foot from gas pedal. Chunky, beefy thread offroad and m/s thread will have too much resistance as car slows down instantly as soon as you lift foot off the gas pedal.

This rolling resistance play very important rolde in fuel efficiency and there is a good 10%-15% difference in fuel mileage for best and worst rolling resistance tires. There is no Z class, but i belive there is class A - G and it's the combination of three things that matter while choosing your tire

Fuel mileage + Wet grip + Noise.

Higher the fuel mileage rating will have worst of wet grip.
Higher the wet grip will have worst the fuel mileage + too much road noise.

Ideal tire selection range for normal road usage in UAE heat:

• Fuel mileage: B-D
• Wet grip: A-C
• Noise: 60-80 db