Today's cars are already fairly sleek, but aerodynamic drag can be further cut by 40–50 percent or more through low-angle windshields, a smooth underbody, a tapered rear end, minimized body seams, and aerodynamically designed air intakes, suspension, and wheel wells. These improvements could be achieved without overly restricting the stylist's freedom to make attractive and distinctive-looking cars. Large improvements could be made by just smoothing the underbody, which is essentially invisible.
Much of the scope for reducing aerodynamic drag is in smoothing the underbody.
Rolling resistance can be reduced by more than 50 percent, thanks not only to ultralight design but also the use of special (but not exotic) tires, wheel bearing assemblies, and brakes. These changes would be mostly transparent to the driver, since low-rolling-resistance tires and suspension systems can be designed to provide traction, comfort, and durability comparable to conventional ones.
