Question: Is it damaging your car to continuously drive with low fuel levels? I've heard that running my gas tank near empty causes the engine to suck up all the junk in the bottom of my tank. Is this true?

Answer: In short, running your tank all the way to empty is no longer a problem like it was in the past and there are a few reasons for this.

Filtering Out the Problems

Fuel filters are more effective than they once were. While filters are an effective means of protecting one’s car from debris problems, filters (usually a protective screen or strainer) do need to be replaced. However, each car manufacturer has different recommendations on the mileage a filter should be changed, so be sure to talk to a professional about this.

If a fuel filter is not properly working, the fuel injectors can get damaged because they are sensitive to gunk. Typical fuel filter problems are from the build-up of gunk that fuel filter has prevented from getting into the engine and therefore disrupting the flow of fuel or the filter begins to disintegrate and the debris are able to get through.

H2NO

In the past, there were concerns that a fuel tank with empty space from being low would allow water condensation to build-up, but this is no longer a problem. Modern cars use an internal canister that fill the fuel tank with air, and  in return, there is much less exposure or potential for outside moisture to occupy empty space.

Additionally, most gasolines today are an alcohol blend, which allows water to be combusted along with gasoline.

The Switch to Plastic

Most fuel tanks today are made of plastic, not metal, so they won’t rust or create any corrosion in the fuel tank like they did in the past.

We’re just saying that most modern cars are not at risk of any problems based on the amount of fuel in the fuel tank because manufacturers have made various tweaks and changes to prevent problems from the past.  

However, only you know your car and what makes you feel comfortable driving. So if you don’t feel comfortable by letting the fuel levels get low, by all means, you won’t do any harm by keeping it full. Drive safe.

Information Resources: CarTalk.com and Bankrate.com