$48.99 USD
MSRP $76.69 36.1% Off
Free Ground Shipping!
In Stock & Ready to Ship!
Find a Dealer

K&N 33-5040 Air Filter

Replacement Filters > Replacement Air Filter
Rating Star 1 Rating Star 2 Rating Star 3 Rating Star 4 Rating Star 5   4.9 out of 5 stars   25 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 33-5040 Air Filter fits some Abarth 124 Spider, Fiat 124 Spider, Mazda MX-5, Mazda MX-5 IV, Mazda MX-5 Miata, and Mazda Roadster 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
Height1.125 in (29 mm)
Outside Length13.563 in (344 mm)
Outside Width5.625 in (143 mm)
Package Contents1 Air Filter
Package Quantity1
Product StylePanel Air Filter
Weight1.1 lb (0.5 kg)
Filter Re-Oiling Amount1.05 oz (31 ml)
Product Box Height13.56 in (345 mm)
Product Box Length7.72 in (196 mm)
Product Box Width1.75 in (44 mm)

K&N 33-5040 Air Filter Product Reviews

Wednesday, February 7, 2018 - Part 33-5040
Had a K&N filter in a Harley Davidson without any issues ar all. Figured i buy one for my new 2017 Abarth Spider turbo. Read a few concerns regarding a K&N adversely affecting MAF sensors. After doing some research I felt comfortable enough to buy a filter. Couple of weeks use and pleased to reveal that no adverse issues have been experienced. Instead I am pleased to say that performance has increased. Prior to changing to a K&N filter my Roadster used to bottom out at 5000 rpm. Now it hits 6500 rpm and i think i could have pushed it to redline 7000 rpm. I put this down to enough air making it's way through to the rest of the engine. It feels a little more perky but not by much. All up I am happy in having purchased the Filter. I have only one suggestion. Please provide adequate installation details such as what side must face where and please state if it needs oiling or if it is factory pre oiled.

Rainer Lucks
Paradise, Australia
Wednesday, January 3, 2018 - Part 33-5040
I was expecting better performance and increased engine noise but have not experienced either of them

John Myklebust
Linden, Belgium
Thursday, November 23, 2017 - Part 33-5040
I put this one into my wife’s 2016 Miata while she’s on vacation. It only took one drive before she asked me if I put in a K&N. I was greatly rewarded.

Al Fleury
San Diego, California
Monday, November 20, 2017 - Part 33-5040
Miraculously cured a low RPM performance problem with my 2017 Fiat 124 Spider. A winner that lives up to advertised performance.

Harold Pawlowski
Glendale, Arizona
Monday, October 16, 2017 - Part 33-5040
One of the first things I do when I purchase a new automobile or Harley- is to order one of your dynamic K&N air filers. Recently installed your filter into my new 2017 Mazda 2L RF touring addition Miata mx-5. Deeper engine/exhaust notes -along w better MPG. Thx Rocko-

Steven Copley
Phoenix, Arizona
Monday, August 21, 2017 - Part 33-5040
It was very easy to locate the filter that I needed and it arrived at my house when it should have. Now my 2016 Miata with a custom exhaust (header, mid-pipe with high-flow catalytic converter, and muffler) along with a custom map loaded in the ECU can breath a little better. 200+ HP out of a 2,300 lb car is fun.

LeRoy Dennison
Riverview, Florida
Friday, August 18, 2017 - Part 33-5040
Has made a great improvement to how the car performs, especially in second gear as it allows the turbo to kick in earlier and has got rid of the the delay that existed below. Well worth the money.

Stuart Hewlett
Coventry, United Kingdom