為何車輛轉彎時會傾斜？

In the diagram above, the school bus is turning right and tilts outward.
Total friction given by tyres and road provides centripetal force for circular motion.

C.M. : center of mass
N : Newton due to action-reaction pairs
f : friction
CW : clockwise
ACW : anti-clockwise

Before flipping over of the school bus,
f1 + f2 +N1 = N2
N2 > N1

Therefore, the car tilts outward during the circular motion.

Image source:
https://xmdemo.wordpress.com/2014/06/29/044-circular-motion-of-cars-and-motorcycles/