[kach22i]

Originally Posted by M_a_t_t

The simplest way to look at it:

Rounded surface creates lower pressure. Look at an air foil, the top surface creates lift by lowering the pressure. Overall shape of the car is rounded, thus creates lower pressure on that surface (varying levels). Low pressure on the top half of the car is lift.

Flip a car upside down and you get down force right?

I found the first few sections of the link below informative.


https://www.sciencedirect.com/topics...rodynamic-lift

Vehicle body aerodynamics
Heinz Heisler MSc., BSc., F.I.M.I., M.S.O.E., M.I.R.T.E., M.C.I.T., M.I.L.T., in Advanced Vehicle Technology (Second Edition), 2002

The aerodynamic lift coefficient CL is a measure of the difference in pressure created above and below a vehicle's body as it moves through the surrounding viscous air..........

14.3.2 Vehicle lift (Fig. 14.20)
When a car travels along the road the airstream moving over the upper surface of the body from front to rear has to move further than the underside airstream which almost moves in a straight line (see Fig. 14.20). Thus the direct slower moving underside and the indirect faster moving top side airstream produces a higher pressure underneath the car than over it, consequently the resultant vertical pressures generated between the upper and under surfaces produce a net upthrust or lift.