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K&N 33-2181 Air Filter

Replacement Filters > Replacement Air Filter
Rating Star 1 Rating Star 2 Rating Star 3 Rating Star 4 Rating Star 5   5.0 out of 5 stars   34 Customer Reviews
  • Designed to boost horsepower and rate of acceleration
  • Can be cleaned and used again
  • High air flow with exceptional filtration
  • Lasts up to 50,000 miles before cleaning is required depending on driving conditions
  • Works with original equipment manufacturer vehicle electronics
  • Emissions legal in all 50 US states
  • Will NOT void vehicle warranty
  • Million Mile Limited Warranty®
K&N's replacement air filters are designed to increase horsepower and acceleration while providing excellent filtration. We make over 1,200 different replacement air filters for the majority of vehicles on the road. These filters are washable and reusable and are custom designed to fit into your existing factory air box. Their drop-in design means adding performance is simple. With most vehicles you simply remove the disposable air filter and replace it with a K&N. See applicable instruction sheet for details. Our stock replacement air filters for street vehicles are covered by our famous K&N Million-Mile Limited Warranty and will be the last air filter your vehicle will ever need.

[More Information on K&N Replacement Air Filters]

Product Specifications

Air Filter ShapePanel
Filter MaterialCotton Gauze
Filter Re-Oiling Amount1.21 oz (36 ml)
Height1.25 in (32 mm)
Outside Length13.688 in (348 mm)
Outside Width5.188 in (132 mm)
Package Contents1 Air Filter
Package Quantity1
Product Box Height17.19 in (437 mm)
Product Box Length8.31 in (211 mm)
Product Box Width1.75 in (44 mm)
Product StylePanel Air Filter
Weight0.9 lb (0.4 kg)

K&N 33-2181 Air Filter Product Reviews

Thursday, May 26, 2016 - Part 33-2181
Great product, fits as good as original, no problems with a much cleaner pulling engine.

Ian Bailey
Isle of Wight, United Kingdom
Monday, May 16, 2016 - Part 33-2181
Replaced both of the standard (Brand Name) air filters on my SL55 Merc with K&N. The outcome was very noticeable. Better throttle response and acceleration. It's like giving your engine a breath of fresh air.

Steve Wills
Ruislip, Middlesex, United Kingdom
Monday, May 9, 2016 - Part 33-2181
EPA gas mileage is rated at 17 mpg city/ 25 mpg highway. I just took a 2500 mile road trip average highway mileage was 31.1. Over 500 miles on a tank of gas. Thanks K & N. I am pleasantly surprised.

Gareth W Lamirand
Thursday, May 5, 2016 - Part 33-2181
The K&N filters arrived as scheduled and I installed them on my 2006 MB SLK350. It is difficult to notice a difference (the existing filters were factory filters and were very clean). The K&N filters fit perfectly and are of a high quality and I fully expect they will perform and help me to keep the car running smooth for a long time.

William Wood
Winchester, Virginia
Friday, April 1, 2016 - Part 33-2181
I have no idea if it's any better or not. But your marketing persuaded me my car will be faster and I like your sticker.

Tuesday, March 15, 2016 - Part 33-2181
Fast delivery, well packaged, quality made product. Exact replacement. The car accelerates super smoothly and you can feel the difference under your right foot, its like you've unblocked your cars intake.

Mark Cudby
Basildon, Russia
Thursday, March 3, 2016 - Part 33-2181
Great so far. I've noticed better throttle response and acceleration. Not too sure about better fuel economy because it really doesn't matter to me! lol

Brien Byrne
Houston, Texas