What are the differences between carburetors, port injection, and direct injection? What are the advantages and disadvantages of each? Why do some cars use both port & direct fuel injection? This video deep dives into the various popular forms of fuel injection. We'll discuss the tuning flexibility of port injection, the advantages of the cooling effects of in-cylinder direct injection, as well as how dual injectors (both port & direct) can offer the benefits of both worlds, and help keep carbon deposits off of intake valves.