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K&N 33-2231 Air Filter

Replacement Filters > Replacement Air Filter
Rating Star 1 Rating Star 2 Rating Star 3 Rating Star 4 Rating Star 5   4.8 out of 5 stars   20 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®
The K&N 33-2231 Air Filter fits some BMW 316Ci, BMW 316i, BMW 318Ci, BMW 318i, BMW 318ti, BMW 320Ci, BMW 320i, BMW 323Ci, BMW 323i, BMW 325Ci, BMW 325i, BMW 325Ti, BMW 325Xi, BMW 328Ci, BMW 328i, BMW 330Ci, BMW 330i, BMW 330Xi, BMW M3, and BMW X3 models. See vehicle applications link for details.
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 oz (30 ml)
Height1.063 in (27 mm)
Outside Length9.375 in (238 mm)
Outside Width6.875 in (175 mm)
Package Contents1 Air Filter
Package Quantity1
Product Box Height9.69 in (246 mm)
Product Box Length7.72 in (196 mm)
Product Box Width1.75 in (44 mm)
Product StylePanel Air Filter
Weight0.8 lb (0.3 kg)

K&N 33-2231 Air Filter Product Reviews

Tuesday, November 8, 2016 - Part 33-2231
Outstanding! There is more aggressive acceleration and power. Highly recommend.

Kabirudeen Salami
South Riding, Virginia
Friday, October 14, 2016 - Part 33-2231
Near perfection every time. Quick turn around, excellent products. They have never failed to perform.

Gary Luce
Lebanon, Kentucky
Wednesday, September 28, 2016 - Part 33-2231
Speedy delivery, easy installation. Car running and sounding great.

John Brown
Wadebridge, Portugal
Tuesday, September 13, 2016 - Part 33-2231
Top product, quick service.

Oliver Dixon
Portsmouth, United Kingdom
Tuesday, August 2, 2016 - Part 33-2231
Super fast delivery and fit perfect.

Bruce Kelly
St. Philip's, Canada
Monday, February 15, 2016 - Part 33-2231
Fast delivery and slight throttle response increase. Well made.

Devon, United Kingdom
Monday, February 8, 2016 - Part 33-2231
Super Service, Superb Product Vic

Vic Pena
Charlottesville, Virginia