Fuel and Lubricant Testing


SPL Notice to Customers

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Contaminated or Mixed Fuel Testing

We perform testing on gasoline and diesel fuel to detect common sources of contamination, including water, dirt, rust, algae, salt, DEF (diesel exhaust fluid), and transmix. Contaminated fuel can cause many problems, particularly for automotive engines. Fuel contamination may cause engine stalling, hard starts or stops, filter plugging or even holes in the fuel tank.

Contamination can have many different causes. If there is water in the fuel, this can cause serious damage. Your fuel may also be contaminated with dirt, rust, or algae. Even if the fuel is clean, if fuel is mixed in the tank - gasoline with diesel, for example - this can cause serious engine damage.

The tests we perform on contaminated fuel generally give yes or no answers to specific questions; there is no one ‘contamination’ test that can both confirm that a fuel sample is contaminated and identify the source of contamination. The best way to test contaminated fuel is to start with the most likely source of contamination and go from there.

You can visually inspect the sample yourself to decide if contamination might be an issue. Put some of your fuel in a clear and clean container and look at it in good light. Look for dirt or other particles in the fuel, either at the bottom of the container or floating in the fuel. This could be dirt or rust or even algae. Also look for separation - layers in the fuel that might be water or mixed fuel. If the color seems different than usual, this can be a sign of mixed fuel or bacteria.

If you don't know what is in your fuel, you can bring or ship your sample to one of our laboratories. Our technicians can examine the sample and give you their recommendations. Our technicians are highly trained and experienced with contaminated fuel. They can assist you in choosing the correct testing for your sample. 

To help you save time and money, we also offer several testing packages for both gasoline and diesel fuel. These test packages include several tests at one discounted price, so that you can have several tests performed to discover the most likely causes of contamination. For example, our Standard Diesel Test Package analyzes diesel for microbial growth, water and sediment and gasoline contamination (by flash point, which is a yes/no result, and by distillation, which can estimate how much gasoline is in the diesel fuel). Gasoline fuel, on the other hand, behaves differently from diesel fuel and has different operating requirements. Our Standard Gasoline Test Package tests gasoline for diesel contamination (by distillation), water content, composition and octane by Petrospec, and density. We offer other test packages as well; contact us to learn more.

We offer a sample shipping kits to help get your sample shipped to our lab. These shipping kits include all the packaging you need to ship fuel safely and the labeling needed to meet government regulations. Learn more about our Sampling and Shipping Kits.

Here is a list of tests that can detect the most common causes of contamination for gasoline and diesel. We also test for other sources of contamination, but these tests are a great place to begin. If you suspect your fuel has been deliberately contaminated by a third party, you may need a different set of testing to determine what’s in your fuel. Contact us today with any other questions you have about testing contaminated fuel.