How do I choose the right fuel filter?

Fuel injectors, carburetors, and electric fuel pumps can be harmed by relatively small particles. To keep your car running at peak performance you need to choose a filter with the right micron rating and element type.

Micron Ratings

A micron is so small it can’t be seen by the naked eye. Micron ratings on filters typically range between 2 and 100. The lower the number, the smaller the particle it will filter out reliably. You don’t always want the lowest micron filter you can get because they can clog up. Follow these recommendations depending on where the filter is and what type of fuel system you have.

• 100 Micron Filters are usually used as pre-filters to protect fuel pumps and keep larger debris from clogging your post-pump filter. They can be mounted in-line before the pump or in the tank. Pre-filters in the tank are often called “sock filters” or “fuel strainers”
• 40 Micron filters are generally used for carbureted engines after the fuel pump. It’s a good idea to use these along with a 100 micron pre-filter even with a mechanical fuel pump.
• 10 Micron Filters are used after the fuel filter with fuel injected engines and must be used along with 100 micron pre-filter.

Filter Element Types

When choosing your filter’s element material you should consider fuel compatibility, reusability, and position in your fuel system.

• Paper filters are often referred to as cellulose filters and are usually disposable.
  • Paper filters should not be used with methanol or fuels containing more than 20% ethanol
• Stainless-steel filters are compatible with all fuels and can typically be cleaned and reused.
• Micro Glass filters are for post-pump use only and are disposable. 

Fuel Filter Elements and Compatible fuels