The engine was built in-house by Koenigsegg, in Ängelholm, based on a modular Ford V8 engine architecture. Koenigsegg re-engineered the entire powerplant in order to reach 655 hp with full OBD and emissions compliance, while maintaining great reliability and drivability.

Among the many changes that were made, the engine was fitted with dry-sump lubrication, forged pistons and connecting rods, larger injectors, merged exhaust headers, ram air intake, a centrifugal supercharger, and a large intercooler. The cylinder heads were reworked and fitted with new camshafts and injectors, with strengthened head bolts to take the higher performance load.

Christian invented and patented the 'Rocket Cat' to maintain a free-flowing exhaust and high power on an engine with catalytic converters fitted.  If the pre-cat created too much back-pressure at high rpm, the overpressure was dynamically bypassed directly to the main cat, which is working at temperature by this point.  The Rocket Cat was a simple, clever solution with no moving parts, and it increased power by nearly 100hp compared to existing solutions at the time. 

The CC8S pioneered the detachable, stowable carbon roof and the dihedral actuation doors that Koenigsegg has become famous for.