Oil Filters 101: Why They're Important and When to Change Them
Most folks think about oil changes in terms of the oil, not the filter. But your oil filter is the unsung hero that prevents those nasty impurities from getting into your engine.
In this guide, we’ll break down what oil filters do, how they work, and when to replace them to keep your engine healthy.
What Does an Oil Filter Actually Do?
An oil filter removes contaminants from the engine oil as it circulates. These contaminants include:
- Dirt and road dust
- Microscopic metal shavings from engine wear
- Carbon buildup from combustion
- Sludge and oxidized oil
By eliminating these particles, the oil can lubricate engine components efficiently without inflicting wear or damage.
What Happens If You Don't Replace Oil Filter?
Not replacing the oil filter means:
- The filter clogs and constricts flow
- The bypass valve activates, unfiltered oil is circulated through your engine
- Dirty oil leads to additional wear, poor fuel economy, and potential failure
Even with premium oil, a dirty filter eliminates the benefit.
Warning Signs Your Oil Filter Is Clogged
Watch for these warning signs:
- Decreased engine performance
- Ticking metallic sound after starting
- Dashboard oil pressure light
- Dirty or sludgy oil on dipstick
If you notice any of these, check your oil and filter immediately.
How Often Should You Change Your Oil Filter?
The general rule: replace the oil filter whenever you replace your oil.
- Conventional oil: every 3,000 to 5,000 miles
- Synthetic oil: every 7,500 to 10,000 miles
- Harsh conditions: dusty roads, short journeys, towing → change more often
🛠️ See our oil change interval chart for guidance.
Spin-On vs Cartridge Filters: What's the Difference?
- Spin-On: Most common. Metal case, screw-on type. Easy to replace.
- Cartridge: Filter element itself, inserted into a reusable case. Popular in European cars.
Functionally, they both work fine — but need to be treated differently when replacing them.
🧰 Purchase both spin-on and cartridge oil filters in our catalog.
Choosing the Right Filter for Your Vehicle
Always choose your filter to correspond:
- Your car's make/model/year
- Engine size and type of oil
- OE requirements or cross-ref tables
Bargain filters can collapse, leak prematurely, or not trap small particles. Use quality brands that are test-proven for performance.
🛢️ Use your filter with Everest or Petromerica oils to realize maximum efficiency.
Bonus Tip: Don't forget the Filter Gasket
Always double check that the old filter gasket taken off with the filter. A stuck gasket can lead to leaks, loss of pressure, or full oil blowout.
Lubricate the new gasket with a small amount of new oil before installation.
Last Reminder: Clean Oil Demands a Clean Filter
Your oil filter is your engine’s first line of defense. Don’t skip it. Replacing it on time can prevent major repairs and extend the life of your vehicle.
Questions about oil and filters? Ask our support team — we’re here to help.