The four-wheel disc brakes fitted to the S281 model have the biggest rotors and stiffest calipers ever fitted to an S281 as standard equipment. Twin-piston aluminum calipers clamp down on 12.4-inch ventilated front brake discs, an increase of more than 15 percent in rotor size compared to last year. In the rear, the brake rotors are 11.8 inches in diameter, more than 12 percent larger than on the 2004 model. In addition, the 2005 rear rotors are vented. A four-channel anti-lock braking system and all-speed traction control provide additional assistance during emergency maneuvers.