Oil Filter Vs. Fuel filter: What Are The Basic Differences?

by Chris Lewis.

Lubrication oils and fuels are a basic need for the engine. The engine depends on lubricants and fuels the same way we rely on food for survival and sustenance. The oil and fuel supplies need to be clean and free from contamination.

It is impossible to get clean engine fluids first hand. Mainly because they come in contact with tiny impurities as they undergo several processes like production. With innovations over the years, the good news is that filtration of these fluids is possible within the car system.

The engineering of the oil and fuel filters makes the filtration process possible and yields engine friendly fluids. Both filters have a vast range of similarities, especially in their designs and functions. When it comes to the smooth running of the engine, the two filters take a big chunk of credits.

However, despite the similarities, the filters display some differences between them. One evident and basic difference is in their name. If they were alike, they would generally identify as “filters.” Therefore, we’ll dive into their detailed specifications and source out their differences.

Fuel Filter

Fuel Filter
Fuel Filter

The filter is responsible for screening out contaminants from the fuel. Some common pollutants that find their way into the fuel include dust, paint, rust, and water particles. If these contaminants find their way to the engine system, they can clog and wear out the engine. That is due to the contaminants' abrasive trait, such as rust and paint particles.

That is why you need to install a high-quality filter to curb the occurrence of such a case. A faulty engine can rip your pockets apart when it comes to repair and replacement too.

Moreover, if the water contaminants reach the engine, the effect will be overheating. Water is not a lubricant. Based on that fact, the engine moving parts will face the strain, and friction between them will lead to overheating.

Key Functions:

  • Prevents clogging of the engine by impurities
  • Curbs corrosion of engine and fuel system
  • Counters interference of engine performance
  • Prevents overheating possibilities at the engine

Location of the Fuel Filter

The filter has no specific mounting place on the car fuel system. The positioning of the filter varies depending on the car model and type of fuel system. Common mounting locations include the fuel system lines, the gas tank, and around the engine.

Common Types of Fuel Filters

Common Types of Fuel Filters
Common Types of Fuel Filters

Primary Filter

The primary filter screens out large particles from the fuel. In the diesel fuel system, they lie between the tank and the fuel pump. The filter trap particles of up to 10 microns in size. Particles such as metal debris and water get filtered out.

Secondary Filter

This filter complements the primary filter. Since the primary filter only filters large particles, this filter picks up the remaining pieces of contaminants in the fuel. It has the capability of screening out finer particles of up to 10 microns.

Canister Fuel Filter

The name itself gives you a hint on the structure design of the filter. It resembles a canister. The canister filter hosts a filtration element on the inside that is responsible for screening the fuel.

Spin-on Filter

The installation location for this filter is at the engine. The filter has threaded end notches that make it easy to fasten them into place hence their name. Installing this kind of filter is a walk in the park experience.

In-line Filter

This type of filter lies inside the fuel line system. The filter features an inlet and outlet openings on both ends. The inlet opening lets in the unfiltered fuel while the outlet opening releases the filtered fuel.

Oil Filter

Oil Filter
Oil Filter

An oil filter is a cylindrical shaped steel casing that houses a filter element. The task of the filter is to filter out impurities mixed up with the engine oil. Same as the fuel filter, screening out of these impurities reduces the risk of wearing out of the engine parts.

The filtered oil gives your engine optimum performance ability. Therefore, you rest assured your engine will run for a long time without developing faults resulting from wear-outs and unnecessary friction.

Highlighted Importance

  • Reduces cost of maintenance
  • Guarantees long engine lifespan
  • Guarantees optimum engine performance

Location of the Oil Filter

Unlike the fuel filter, this filter works its magic at the engine. However, the location of the filter at the engine can vary from one vehicle to another. Depending on the model, they rest at the top, bottom, or side of the engine.

Common Types of Oil Filters

Full flow filter

Also known as a primary filter, they are less restrictive; therefore, they filter out 100% of the oil. The reason behind their less restrictive nature is to be in line with the engine requirement without denying the engine’s craving for oil.

Bypass filter

Also known as the secondary filter, it filters out finer particles contained in the oil. Just like the fuel filter, the primary and secondary oil filters work hand in hand in some engine systems.

Convectional filter

The filtration medium material uses conventional medium materials such as fiberglass and cellulose, thus their name. The working of this filter is the same as the Bypass filter.

Spinner filter

This type of filter is cylindrical and rotates. The rotation of the filter screens out contaminants from the oil by the aid of centrifugal forces.

Thermal filter

Oil first undergoes the normal filtration process at this filter. Afterward, the filtered oil gets heated up to eliminate the remaining particles in the oil stream.

Differences between the Oil Filter and the Fuel Filter


Depending on the fuel system design, the fuel filter has multiple mounting places. The engine, fuel system lines, and the gas tank can be hosted for the filter. The oil filter, on the other hand, has its location only at the engine.

Type of fluid they filter

Even though both filters carry out the same function, they do it on different engine fluids. The fuel filter screens out impurities in the fuel while the oil filter screens the engine oil.


Oil filters have the same size, regardless of the type. Contrary to that, the fuel filters vary in size depending on their location on the fuel system. Additionally, oil filters are a little bigger than their counterparts


The oil and fuel filter carry out the same functions but on different fluids. Despite their differences, both filters are a must-have for your car. Without these, be sure you will be a regular at the garage and automobile repair station.

Knowing the types and the working of these filters, you are in a better position to make the right judgment when choosing one. However, it is also essential that you consult your manufacturers' manual, so you don’t get mixed up.

About Chris Lewis.

Thoughts on "Oil Filter Vs. Fuel filter: What Are The Basic Differences?"