Question

A car is fitted with 6 * 14 wheels and 185/65 R 14 tires on them. What is the rolling radius of the original tire?

(a) 398.05 mm

(b) 298.05 mm

(c) 288.05 mm

(d) 278.05 mm

This question was posed to me during an internship interview.

My question is based upon Wheel and Tire in division Engine Construction & Wheel Assembly of Automobile Engineering

Answer 1

Right answer is (b) 298.05 mm

The best I can explain: Radius of the wheel = ½ * 14 = 7 in = 177.8 mm. Section height of tire = 0.65 * 185 = 120.25 mm. Rolling radius of the original tires = 177.8 + 120.25 = 298.05 mm.