Pitch stiffness is the mechanism that suspension designers use to control the vehicle's pitch (rotation about y-axis). The units of pitch stiffness are Nm/deg. The inertial force at the vehicle's c.g. creates a moment that attempts to pitch the car's body, but the springs of the car counteract it. Pitch stiffness works exactly the same way as roll stiffness, and the formula is similar: 0.5*(Front Ride Rate + Rear Ride Rate)*(Wheelbase)^2.