How to Clean a Dirty Fuel System and Save on Repairs

Fuel additives can remove carbon deposits and contaminants to improve fuel economy and engine performance.

Published on Feb. 27, 2026

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Over time, a car's fuel system can become dirty with carbon deposits and debris, leading to clogging and potential damage. Using fuel injector cleaners or fuel system cleaners added to the gas tank can help remove these contaminants and improve fuel economy, throttle response, and reduce emissions.

Why it matters

Maintaining a clean fuel system is important to prevent costly repairs down the line. Dirty fuel injectors and fuel lines can lead to decreased performance, reduced fuel efficiency, and even engine damage if left unchecked.

The details

Fuel injector cleaners and fuel system cleaners are additives that can be poured directly into the gas tank. Fuel injector cleaners focus on removing deposits from the fuel injectors, while fuel system cleaners clean the entire fuel system. Experts recommend using these products every 5,000 miles or so to keep the system running efficiently.

  • Fuel additives should be used when the gas tank is around a quarter full.
  • Many fuel system and injector cleaners recommend using them around every 5,000 miles.

The players

Keenan Thompson

A car culture reporter for the Detroit Free Press.

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What they’re saying

“Filling up a car with gas is second nature for most drivers. But what is not as well known is how dirty a car's fuel system can get over time.”

— Keenan Thompson, Car culture reporter (Detroit Free Press)

The takeaway

Regularly using fuel system and injector cleaners can help maintain a car's fuel system, improve performance, and prevent costly repairs down the line.