What is the reason for the purring noise of BMW 3 Series?

The reasons why BMW 3 Series purrs are: the influence of body vibration; Resulting in abnormal wear of hub bearings. Take the modified 320i sports suit of BMW 3 Series 202 1 as an example. The length, width and height of the car are 47 19mm, 1827mm and 1459mm respectively, and the wheelbase is 2851mm. The BMW 3 Series 202 1 modified 320i sports suit is equipped with a 2.0t turbocharged engine, with the maximum power 1 15kw and the maximum torque of 250nm, matching the 8-speed automatic manual transmission. The front suspension type is the front axle with double ball joints and spring strut, and the rear suspension type is multi-link independent suspension, load-bearing body structure and front drive mode. Million car purchase subsidy