Fuel Filters 101Just like the food and drinks that we consume on a daily basis are washed, cleaned, processed, and prepared, fuel that enters a vehicle's engine must follow a similar pattern to ensure peak operating efficiency and effectiveness. That's where a fuel filter enters the picture, as it's a crucial middleman of sorts between the gasoline we pump into our fuel tanks and the engine itself. This post is designed to take a closer look at fuel filters, the role they play, how to change them, and the best ones to purchase.

Fuel Filters: The Basics

Think of a water filter for a moment. You place it over the sink faucet, and it works to filter out potential contaminants in the water supply so that it's safe for drinking. This, in turn, ensures that you're drinking a healthy source of water and reducing the risk of falling ill from contaminants. Fuel filters serve a similar purpose, just in a vehicle setting. Unfiltered fuel often contains a variety of contaminants, which could harm your engine and reduce its efficiency were they to reach it. Things like paint chips and dirt are often byproducts that enter the fuel when it's being processed in a refinery. Then, there's potentially even more grime, particles, and even rust in a vehicle's fuel tank itself that can contaminate the fuel. A good fuel filter ensures that none of these contaminants get to the engine, so the engine is only burning clean fuel.

However, a bad fuel filter will make the fuel pump worker harder, reduce engine power, and possibly even harm the engine. And just like the water filter example that we mentioned above, fuel filters too become clogged and need to be replaced. That's why it's imperative to ensure that your fuel filter is in good condition.

How Do I Know It's Time to Change My Fuel Filter?

Any component that's designed to capture contaminants is going to eventually need to be changed, and the general rule of thumb when it comes to fuel filters is to replace them every 20,000 to 40,000 miles. That's a pretty wide range, however, so it's also important to take note of various signs and symptoms that may indicate the need for replacement. These include:

    • Abnormal idling: Clogged fuel filters typically give way to abnormal idling, largely because the engine is unable to draw a consistent fuel flow from the supply line.
    • Poor starts: If your vehicle isn't starting at all or it has become difficult to start, it's always a bit of a process to discover the culprit. Bad spark plugs, a bad engine filter and a depleted battery are components to inspect, but don't underestimate the importance of your fuel filter in all of this. Remember, fuel filters work by helping the engine draw fuel. If it's clogged, it might be getting an insufficient amount - or no fuel altogether. If your car is hard starting, don't put off addressing the issue - you don't want your engine to die when you're driving and put your safety and the safety of your fellow motorists at risk.
    • Slow acceleration: If you step on the gas and can feel the engine hesitating to accelerate, it could be because it's not getting the fuel it needs to make the jump in speed. You'll likely notice this more in city driving environments where you're more frequently stopping and going.

How to Change a Fuel Filter

Fuel filters are an affordable component that only typically cost $10-$30 for a replacement, but having one replaced by your mechanic will usually run between $100 and $150 thanks to labor costs. However, you can save on labor costs by replacing it yourself - and it's a fairly easy DIY task. Here's a brief overview of how to replace a fuel filter, assuming it's located under the hood and not in a vehicle where it's part of the pump inside the fuel tank itself. Before you get started, make sure you have the replacement filter (per your vehicle manufacturer's recommendations), a wrench set, a fuel line disconnector, drain pan and a screwdriver.

    • Start by relieving the fuel pressure. Though this can be done a few ways, it's easiest to find and push the pressure relief valve in the fuel rail.
    • Position the drain pan underneath the existing fuel filter to capture any excess fuel that may spill out when you remove it.
    • Remove the safety clips from the fuel filter and fuel lines.
    • Get your fuel line disconnector and position it between the top of the existing fuel filter and fuel line. Use it to push out the tabs holding the fuel line in place.
    • While you're holding the disconnector against the fuel line with one hand, use your free hand to pull the fuel line out. Next, remove the old filter.
    • Use a wrench to free the clamp that holds the filter to the vehicle's frame, then take out the old filter.
    • Use some sort of lubricant on both ends of your new filter, then position it back into the clamp. Tighten the clamp back into place.
    • Reconnect the fuel lines into the new filter.
    • Start up the engine and monitor the new filter to ensure that it's not leaking.

Best Fuel Filters to Buy

Like with most automotive components, what you put into the vehicle is what you'll get out of it. That's why we recommend only going with parts produced by proven automotive suppliers, and staying away from cheaper, generic brands. For this reason, three brands we recommend when it comes to replacement fuel filters are Hastings, Fram, and AC Delco.

Fram is arguably the brand most synonymous with fuel filters and tends to offer the most affordable fuel filters with good quality to boot. Hastings is your middle-of-the-road fuel filter provider, and AC Delco offers fuel filters at moderate prices as well, even if the brand isn't typically associated with fuel filters. What's nice about these name brand suppliers is that it's easy to find replacement filters for even older vehicles.

For example, AC Delco's GF643 direct fit filter is an ideal replacement for many mid-sized pickup trucks produced in the mid-1990s. The same can be said about Fram's G3850 filter. In mid-sized older sedans, a Hastings GF258 is ideal for a six-cylinder engine. For four-cylinder engines, filters such as an AC Delco GF578F and a FramG7315 are adequate models.