The oil filter is the least glamorous part of an oil change — it’s a – component that gets thrown away every change. But the filter you use matters more than most drivers realize. It’s the only thing standing between unfiltered engine oil full of metal particles, combustion soot, and debris, and the precision-machined surfaces of your engine. At Norm’s Auto Clinic, we use quality filters on every vehicle, and here’s why it matters.
What the Oil Filter Actually Does
Engine oil continuously circulates through the oil filter, which contains a pleated filter media (paper, synthetic, or micro-glass fiber) that captures particles above its filtration rating. A quality filter captures particles as small as 15–20 microns; premium filters capture down to 10 microns. For reference, a human hair is about 70 microns in diameter — the particles damaging your engine are invisible.
Beyond filtration, the oil filter contains a bypass valve that opens when the filter is clogged or during cold starts when viscous oil can’t pass the media quickly enough. This ensures oil keeps flowing rather than starving the engine. It also contains an anti-drainback valve that prevents oil from draining out of the filter when the engine is off, ensuring rapid pressure buildup on restart — when most engine wear occurs.
Cheap Filter vs Quality Filter — Real Differences
- Filter media quality — Cheap filters use coarser media that lets more particles through; premium filters use micro-glass or synthetic media for finer filtration and longer life
- Bypass valve integrity — Cheap bypass valves can stick open (unfiltered oil) or stick closed (oil starvation); quality valves open and close reliably at specified pressures
- Anti-drainback valve — Many cheap filters have minimal or no anti-drainback protection; the filter drains down overnight and the engine runs unlubricated for a fraction of a second on cold starts — repeatedly, over years of service
- Structural integrity — Cheap filter cans can deform or leak at the gasket under high pressure spikes
At Norm’s, we use OE-quality or better filters on every vehicle — not the cheapest item we can order in bulk. When you bring your vehicle to us, the difference in filter cost is already included in our service price. We don’t cheap out on components and pass the engine wear on to you. Call (918) 279-8100 or visit 19 N. Broadway, Coweta, OK 74429.