The difference between Techron Fuel Injector Cleaner vs Fuel System Cleaner is mainly seen in what systems they target. While both are engine cleaners, Techron Fuel Injector Cleaner focuses on, you guessed it, the fuel injectors. It contains solvents that dissolve and remove debris from the fuel injectors which works to cool your engine down and start quicker.
The Fuel System Cleaner targets the fuel system, or the fuel line and gas tank. The chemicals in the system cleaner break down and remove dirt and water from the gas tank and engine. This gives your engine an overall longer lifeline with less wear.
These can be used on either old or modern engines, so no matter what car you’re riding with, these cleaners will be a good investment in extending the engine’s life.