Its the fact your comparing cars that are going after to different types of buyers. If you take just about any make or model of car and drive a sporty version vs the regular car you will notice a difference.. For example if you had the chance to go drive a 2008 Grand Prix GXP and then drive a regular Grand Prix you would notice a huge difference. Also if you was to Go drive a Limited Taurus it would have the softer ride vs any SHO. Its a combo of the Wheels, smaller side walled tires, firmer parts and pieces in the suspension.. Shocks, struts, springs, bushings, ect.