The engine was built in-house by Koenigsegg in Ängelholm based on a modular Ford V8 engine architecture. In order to reach 655 hp with full OBD compliance while meeting emissions regulations and having great reliability and drivability, Koenigsegg really had to re-engineer most of the engine.

The engine was fitted with dry-sump lubrication, forged piston and connecting rods, larger injectors, merged exhaust headers, ram air intake, centrifugal supercharger with a large intercooler (among many engineering changes). The cylinder heads had to be reworked and fitted with new camshafts and injectors. Head bolts had to be strengthened and the list goes on.

In order to have a free-flowing exhaust to meet the power needs and at the same time fit catalytic converters, Christian invented and patented the ‘Rocket cat’ principle. The system worked in a way that when the pre-cat created too much back pressure at high rpm, the overpressure was dynamically bypassed/overflowed directly to the main cat, which is fine as the main cat is fully warm at this point. A simple, clever solution with no moving parts. This solution increased power by nearly 100 hp compared to existing solutions.

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