Should You Use Lead-Reducing Fuel Additives?

A FLYING reader asks our A&P author if using these fuel treatments will help their aircraft.

Q: I fly a Champ with a Continental C-85 engine, and I am confused about the benefits of fuel treatments like TCP that reduce lead deposits from 100LL. My spark plugs look clean. Is it just a good idea to use lead-reducing fuel additives anyway?

A: There is no secret about the harmful effects of lead. I recently spoke with George Braly of General Aviation Modifications Inc. (GAMI), who is currently running tests for their unleaded avgas alternative G100UL. Initial teardowns of the tested powerplant showed cleanliness far superior to that of leaded 100LL. Lead is a dirty business, a foul element (no pun intended), and better left to history.

Aircraft Spruce & Specialty carries a wide range of lead-reducing additives, including TCP. While we cannot review each one individually, one key indicator to look for when choosing an aircraft product is FAA approval. It is always a good idea to stay in line with the feds.

Alcor’s TCP stands for tricresyl phosphate, which is an effective tetraethyl lead (TEL) scavenger. It is rated for many types of powerplants and requires no additional approvals. The company claims it will reduce plug fouling. You mention in your question that you typically do not have an issue with fouled plugs. Are you considering TCP as a preventative measure? If so, a lead reducer like TCP Fuel Treatment could be an effective way to bridge the gap until more inclusive unleaded avgas approvals are signed.

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