With emissions standards getting ever stricter, many had thought high-performance supercars and hypercars with internal combustion engines would be on their way out. However, this is not the case, at least not yet.

Sure, a new-generation of all-electric or hybridized hypercars are already out there, and many more our coming our way, but there are still a number of roaring, gas-guzzling alternatives out there, none more impressive than those from Koenigsegg.

As this video from Engineering Explained reveals, the niche Swedish car manufacturer has created innovative solutions to ensure its powerful cars are road legal, particularly in U.S. states with extremely tight emissions rules such as California.

Also Read: Until Your Jesko Arrives, Get Your Koenigsegg Fix With The 1,341HP Agera RS Draken

All modern cars come outfitted with catalytic converters to help clean up hot exhaust gases. Many vehicles also feature a pre-cat that is used when the engine is cold and the main catalytic converter hasn’t yet reached operating temperature. Unfortunately, this pre-cat cannot be disengaged once the main cat is working, robbing a vehicle of valuable power.

Koenigsegg’s first solution to this came in 2004. The company developed a small pre-cat suspended in the exhaust chamber. What this means is that, at low loads, the vehicle funnels its exhausts gases through the pre-cat, but at higher ones, and when the car is warmed up, they go around the pre-cat and straight to the main catalytic converter. This alone results in a gain of about 100 HP.

In 2011, Koenigsegg patented another tech, which was used in the Agera RS. This time, the exhaust system uses bypass valves to point exhaust gases at the pre-cat when the vehicle is warming up before switching off the valves and directly gases to the main cat when everything is warmed up. The company says this results in an even more remarkable power bump of 300 HP!