TerraClean's Optima Fuel System Cleaner and Intake Valve Deposit Cleaner are complementary products to the company's Fuel System Decarbonizer. Designed for direct injection engines, the Intake Valve Deposit Cleaner safely and effectively cleans intake valves and combustion chambers, helping to restore engine performance and mileage, improve fuel economy, eliminate cold carbon knock and help reduce emissions. The Optima Fuel System Cleaner is safe for all fuel injectors, carburetors and fuel system components and also helps improve fuel economy and performance and lowers harmful emissions.