From the Chevron Techron website: "Techron® Concentrate Plus, Complete Fuel System Cleaner, is designed for gasoline carbureted or fuel injected spark ignition engines. To keep the entire fuel system clean, use Techron Concentrate Plus, Complete Fuel System Cleaner, every 3,000 miles (4,800 km) or at scheduled oil change intervals, not to exceed twice per oil change."
I have difficulty imagining an engine that would need more. Have been a Techron user since at least 1991.