K&N makes filters for most common vehicles, but you need your vehicle's year, make, model, and engine size to find the correct one

K&N produces oil filters for passenger cars, trucks, and motorcycles across dozens of manufacturers. Their filters use a synthetic media designed to flow more oil while still trapping particles, and they're sold at auto parts stores, online retailers, and some dealerships. But K&N doesn't make a universal filter — each vehicle needs a specific part number, and ordering the wrong one wastes money and leaves you without protection.

The search process is straightforward if you have your vehicle information ready. K&N's website includes a filter finder tool, and most auto parts retailers (AutoZone, O'Reilly, NAPA, Advance Auto Parts) have their own search functions that will show K&N options alongside other brands. You can also search by part number if you already know it, or by your vehicle's specifications if you don't.

Key Takeaways

  • K&N oil filters are vehicle-specific; you must know your car's year, make, model, and engine displacement to find the right part number.
  • The K&N website has a dedicated filter finder tool that narrows results by vehicle type in seconds.
  • Auto parts retailers like AutoZone and O'Reilly let you search by vehicle or part number and show K&N filters alongside competitor options and pricing.
  • If you don't know your engine size, your vehicle's registration, owner's manual, or a quick call to a dealership service department will provide it.
  • K&N part numbers are printed on the filter itself, so if you've used one before, you can order the same number without re-entering vehicle data.

Using K&N's Official Filter Finder

K&N's website includes a filter search tool at knfilters.com. Click the oil filter section, then enter your vehicle's year, make, and model from dropdown menus. The tool returns the correct part number, a photo of the filter, and a list of retailers that stock it.

This method is fastest if you're starting from scratch, because K&N's database is complete and the dropdowns prevent you from entering mismatched information. The tool also shows you the filter's specifications — thread size, bypass valve setting, and media type — so you can confirm it matches what your owner's manual recommends.

One limitation: the K&N website doesn't always show current pricing or real-time stock levels. It tells you where to buy, but you'll need to visit each retailer's site to compare prices or check availability in your area.

Searching at Auto Parts Retailers

AutoZone, O'Reilly Auto, NAPA, and Advance Auto Parts all have search functions that let you enter your vehicle information and filter results by brand. These searches are useful because they show you K&N filters side-by-side with Fram, Mobil 1, Motorcraft, and other brands, so you can compare prices and read customer reviews in one place.

At AutoZone or O'Reilly, enter your vehicle year, make, and model, then filter the results to show only K&N. The page will display the part number, price, and whether it's in stock at your local store or available for shipping. Many retailers offer same-day pickup if you order before a certain time.

NAPA's search works similarly but often includes fitment notes — for example, whether the filter fits vehicles with or without a turbocharger, or whether it's compatible with synthetic or conventional oil. These details matter if your vehicle has multiple engine options.

Finding Your Vehicle Information If You Don't Have It

Your vehicle's year, make, model, and engine size are printed on your registration or driver's license. If you don't have those documents handy, open your owner's manual — the first few pages usually list engine displacement in liters or cubic centimeters. For example, a 2.0L four-cylinder or a 5.7L V8.

If you can't locate the manual, call your vehicle's dealership service department with your VIN (Vehicle Identification Number, printed on your registration or visible on the dashboard). They can tell you the engine size in under a minute. You can also use free VIN decoder websites, though dealership confirmation is more reliable.

Some vehicles have multiple engine options depending on the model year or trim level. For instance, a 2020 Honda Accord might come with a 1.5L turbo or a 2.0L naturally aspirated engine. Make sure you're entering the correct displacement for your specific car, not just the model name.

Searching by Part Number If You Already Know It

If you've used a K&N filter before, the part number is printed on the filter itself — usually on the top or side. K&N part numbers typically start with "HP" or "PS" followed by numbers. For example, HP-1008 or PS-2002.

You can search for this part number directly on K&N's website, AutoZone, O'Reilly, or any other retailer's search bar. This bypasses the vehicle information step entirely and gets you to pricing and availability in seconds. It's also a good way to confirm you're ordering the exact same filter you've used before, without risk of accidentally selecting a different engine variant.

Part numbers don't change unless K&N redesigns the filter, which is rare. If you've been using the same filter for years, the same part number should still work — though it's worth double-checking against your current vehicle's specifications, especially if you've had engine work done or modified your vehicle.

Understanding K&N Filter Specifications

K&N oil filters come in different thread sizes and bypass valve settings. The thread size — usually 3/4-16 or 13/16-16 — must match your engine's filter housing. The bypass valve setting determines at what pressure the filter opens to allow unfiltered oil through if the filter becomes clogged. Most K&N filters use a 7 PSI bypass, but some high-performance applications use 10 or 12 PSI.

Your owner's manual specifies the correct thread size and bypass pressure for your vehicle. K&N's product pages list these specs, so you can confirm before ordering. Installing a filter with the wrong thread size won't work — it won't screw on. Using the wrong bypass pressure won't cause when ready damage, but it can affect oil flow and filter life.

K&N also makes filters with different media types: standard synthetic, high-flow synthetic, and specialty formulations for racing or extreme conditions. For most drivers, the standard K&N filter is appropriate. High-flow versions are marketed for performance driving, though the difference in everyday driving is minimal.

Comparing K&N Filters to Other Brands During Your Search

When you search at a retailer like AutoZone or O'Reilly, you'll see K&N filters listed alongside Fram, Mobil 1, Motorcraft (Ford's brand), Mopar (Chrysler's brand), and others. K&N filters typically cost more than budget Fram filters but less than or similar to premium synthetic filters from Mobil 1 or manufacturer-branded options.

The price difference reflects K&N's synthetic media and higher flow rate. Whether that difference matters depends on your vehicle, driving habits, and maintenance schedule. Your owner's manual specifies the oil type (conventional or synthetic) and change interval your engine is designed for; the filter you choose should support that schedule, not extend it beyond what the manufacturer recommends.

Reading customer reviews on retailer sites can help you understand real-world performance, but remember that filter reviews often reflect user expectations rather than actual filter quality. A filter that costs more may receive higher ratings straightforward because the buyer expected better performance, not because it objectively performs better.

Frequently Asked Questions

What if my vehicle has multiple engine options and I'm not sure which one I have?

Check your owner's manual first — it lists engine displacement on the first few pages. If you don't have the manual, call your dealership service department with your VIN. They can confirm your engine size in under a minute. Don't guess, because installing the wrong filter can cause fitment problems or inadequate oil flow.

Can I use a K&N filter from a different vehicle if the thread size matches?

Thread size matching is necessary but not sufficient. The bypass valve pressure and filter capacity must also match your engine's specifications. Using a filter designed for a different vehicle can result in incorrect oil flow or pressure regulation. Always use the filter specified for your exact vehicle.

Do I need to use a K&N filter, or can I use a different brand?

Your owner's manual specifies oil type and change interval, not a specific filter brand. Any filter that meets your vehicle's thread size, bypass pressure, and capacity requirements will work. K&N is one option; Fram, Mobil 1, Motorcraft, and others are equally valid if they're the correct part for your vehicle.

Where is the cheapest place to buy a K&N filter?

Prices vary by retailer and change frequently. AutoZone, O'Reilly, NAPA, Advance Auto Parts, and online retailers like Amazon all carry K&N filters. Use each retailer's search function to compare prices for your specific part number. Factor in shipping costs and delivery time if you're ordering online.

What if the K&N filter finder doesn't show my vehicle?

K&N makes filters for most common vehicles, but not every model or year. If your vehicle doesn't appear in their finder, try searching at AutoZone or O'Reilly — they may carry a K&N filter for your vehicle even if K&N's own site doesn't list it. If no K&N filter exists for your vehicle, you'll need to choose from other brands that do make a filter for your engine.