The Ferrari 550 Maranello’s Fuel Cooling System
A bit of car trivia I learned: The Ferrari 550 Maranello (1996–2002) had an interesting way of delivering fuel to its front-mounted V12 engine. It used a relatively early Bosch Motronic fuel injector system that used a high-pressure common rail.
Fuel was carried from the fuel tank in the back of the car and pumped into a pair of rails in the engine bay at maximum pressure. Valves would then inject fuel as needed into the cylinders. Whatever fuel was left was pumped back into the fuel tank in the back through a set of return lines.
But there’s a problem: fuel coming back from the engine would be hot. Over time, the fuel tank would get very hot, which would not be great. So there must be a way to cool off the fuel before dumping it back into the tank.

Enter: the Ferrari Fuel Cooling System. In the return line, Ferrari inserted a pair of heat exchangers, labeled as Part 13 in the image above.
The question was: With what do you cool the fuel?