Most drivers know when to change their oil. But the other maintenance items — filters and spark plugs — tend to get overlooked until something goes wrong.
Here’s the thing: these are some of the cheapest parts on your vehicle. And when they’re neglected, they cause some of the most expensive problems.
This guide covers everything you need to know — four filters, one plug, and exactly when to replace each one.
1. Engine Air Filter
Your engine needs a precise mix of air and fuel to run. The engine air filter makes sure that air is clean — trapping dust, debris, and particles before they can enter and damage your cylinders, pistons, and valves.
A clogged engine air filter chokes your engine’s airflow. And when airflow is restricted, everything suffers.
Signs it needs replacing:
• Drop in fuel efficiency — your engine burns more fuel when it can’t breathe properly
• Sluggish acceleration or poor throttle response
• Rough idle or engine sputtering
• Check engine light triggered by low airflow sensors
• The filter looks gray or brown when you pull it out
How often: Every 15,000 to 30,000 miles. Check it at every oil change — it takes less than a minute to inspect visually.
2. Oil Filter
Your oil filter keeps your engine oil clean as it circulates through hundreds of moving parts. Every pass through the engine, oil picks up metal particles, carbon, and debris. The filter catches it all before it goes back through.
A filter that’s past its limit doesn’t just stop working — it can bypass contaminated oil directly into your engine.
Signs it needs replacing:
• Dark, gritty oil on the dipstick
• Oil pressure warning light
• Engine running hotter than normal
• Metallic knocking or ticking sounds
• You’ve hit your mileage interval
How often: Every oil change — typically every 5,000 to 10,000 miles. Always replace the oil filter and engine oil together. Changing one without the other defeats the purpose.
4. Cabin Air Filter
The engine air filter protects your engine. The cabin air filter protects you.
It filters everything entering your vehicle through the heating and air conditioning system — dust, pollen, smog, mold spores, and exhaust particles. It’s one of the most skipped maintenance items on the list, and one of the most noticeable when you finally replace it.
Signs it needs replacing:
• Weak airflow from vents even on high fan settings
• Musty or stale smell when running the AC or heat
• More dust accumulating on interior surfaces than usual
• Allergy symptoms that seem worse inside the vehicle
• The filter looks dark and compacted when you pull it out
How often: Every 15,000 to 25,000 miles, or once a year — whichever comes first. Replace sooner in high-pollen, high-dust, or high-pollution environments.
5. Spark Plugs
Spark plugs fire the ignition that starts every combustion cycle in your engine — thousands of times per mile. When they’re working well, you never think about them. When they start to wear, your engine tells you in ways that are hard to ignore.
Signs they need replacing:
• Engine misfires — jerking or stumbling during acceleration
• Rough idle, especially at a stop
• Slow or hard starts, particularly in cold weather
• Drop in fuel economy with no obvious cause
• Sluggish throttle response under load
How often:
• Copper plugs: every 20,000 to 30,000 miles
• Platinum plugs: every 60,000 miles
• Iridium plugs: every 80,000 to 100,000 miles
Always replace with the plug type your vehicle was engineered to run. Heat range, electrode gap, and thread specs all matter.
Why OEM Matters for All of These
Every part on this list needs to match your vehicle’s exact specifications — not a range of vehicles, not a close approximation. Your engine.
Every part on this list needs to match your vehicle’s exact specifications — not a range of vehicles, not a close approximation. Your engine.
OEM filters and plugs are built to the tolerances your vehicle was engineered around. An aftermarket alternative that doesn’t seal correctly, flow at the right rate, or fire at the right heat range doesn’t just underperform — it can cause damage that costs far more than the part itself.
For maintenance items this close to your engine, OEM is the only standard worth trusting.
The Peakline Standard
At Peakline Performance Co., we carry OEM filters and spark plugs built to your vehicle’s exact specifications. Whether you’re due for a routine change or chasing down a performance issue, we have the right part — exact fit, factory quality.
At Peakline Performance Co., we carry OEM filters and spark plugs built to your vehicle’s exact specifications. Whether you’re due for a routine change or chasing down a performance issue, we have the right part — exact fit, factory quality.
By Peakline Performance Co.
Shop our full catalog and find the right OEM parts for your vehicle today.