system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do flames come out the exhaust of high performance cars?

So, I'm looking through Instagram, and I follow a lot of car accounts and i saw a video of a McLaren shooting at least 4 inch flames out of its exhaust pipes in a constant stream. What's going on and why does this happen?
gpt
The cars are tuned for maximum power without regard to efficiency.  Lots of fuel gets dumped into the combustion chambers to get a big explosion to move the pistons.  Not all of the fuel gets burned.  Leftover fuel can ignite in a hot exhaust system, causing the flames you see coming out of the exhaust tips.