The CCX features a completely new set of body and interior parts. The new body incorporates a new front bumper design, engineered to function well in the stringent 2.5 mph bumper test, including enhanced brake cooling, fog lamps and US side position lights. The front lamps have been slightly redesigned to suit the new bumper line.
The engine in the CCX retains the incredible performance and power of the CCR engine, while running on US 91 octane fuel and complying with California emission regulations. In order to reach this challenging goal, extensive rework had to be done to emission related items, such as new cylinder heads with larger valve area and more optimally flowing cylinder head ports. Dual smaller injectors per cylinder were integrated, as well as new camshafts, a new carbon fiber individual runner intake plenum, a new engine management system, updated fuel and EVAP system. New exhaust system where the catalytic converters are moved closer to the engine for earlier light-off time. A returnless fuel system has also been implemented with pumps integrated into the new fuel tank. All in all, a heavy rework in order to retain the unique performance of the CCX engine and at the same time comply with the strictest emission regulations in the world.
Source: Koenigsegg Press Release