Fuel is full of particles that you don’t want entering your carburetor, EFI system, or engine. The best way to prevent unwanted particles from damaging your fuel system is to use fuel filters. We spoke with Jim Craig from Weldon High Performance about different types of fuel filters, and where you should place them in your fuel system.

Fuel filters come in different sizes, have different element types, and micron ratings. You’ll want to pay attention to the micron rating the most. The micron rating indicates what size particles the filter is able to catch that is inside the fuel. The smaller the number, the smaller the particles the fuel filter will capture.

The micron rating is an important part of which fuel filter you select, but where you place the filter is actually more important, according to Craig.

“The larger number, up to 100 microns and no lower than a 40, should be placed between the fuel cell and the fuel pump. The smaller number — up to 40 microns in a carbureted application, but a 10 micron is preferred especially in EFI applications — is placed between the pump and fuel injectors or carburetor deadhead regulator. There are some EFI injector companies that require a 6-micron filter rating to prevent damage to their injectors.”

Fuel filters are available with a paper cellulose element as well as a stainless steel element. If you’re using a non-oxygenated fuel the paper element will work fine. These filters are less expensive than filters that use a stainless steel element, however, they can’t be cleaned like the stainless steel filters can. If you’re using an oxygenated fuel, a stainless steel filter must be used due to the chemical makeup of these fuels.

So, which micron size is best for your application?

“For an EFI application, you’ll want to use at least a 10-micron filter before the injectors. This allows the filter to take the hit and collect anything in the fuel rather than the injectors. For a carbureted application, you can use anything between 10 to 40 microns before the carb or deadhead regulator, depending on how the system is actually plumbed,” Craig states.

Weldon’s fuel filters are all assembled in the USA with high-quality components. Craig explains why Weldon’s filters are a great choice for high-horsepower engines.

“Our stainless and paper cellulose filters use stainless steel end caps and epoxy that is compatible with alcohol fuels. All of our 10-micron stainless elements contain a stainless perforated core to prevent the filter from collapsing under the extreme fuel pressures seen in some EFI systems. Our filter elements can also be interchanged with other filter assemblies currently available in the market.”