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K&N E-0644 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   11 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 E-0644 Air Filter fits some Ford F250 Super Duty, Ford F350 Super Duty, Ford F450 Super Duty, and Ford F550 Super Duty 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 ShapeOval
Filter MaterialCotton Gauze
Height8.938 in (227 mm)
Inner WireNo
Outside Length9.25 in (235 mm)
Outside Width6.5 in (165 mm)
Top StyleRubber
Top MaterialNone
Flange Length0.281 in (7 mm)
Package Contents1 Air Filter
Package Quantity1
Product StyleOval Air Filter
Weight4 lb (1.8 kg)
Filter Re-Oiling Amount8.3 oz (246 ml)
Product Box Height12.06 in (306 mm)
Product Box Length12 in (305 mm)
Product Box Width8 in (203 mm)

K&N E-0644 Air Filter Product Reviews

Thursday, February 22, 2018 - Part E-0644
Amazing filter.

Zachariah Riley
Phoenix, Arizona
Monday, February 5, 2018 - Part E-0644
I am very happy with the filter. I have seen a difference already in the performance of my truck.

Michael Norrod
Cheyenne, Wyoming
Wednesday, January 17, 2018 - Part E-0644
I have only had the filter in the truck for about a month but so far so good. During this time, I have not towed our travel trailer with it in so I can't comment on the upper rpm level performance of it as yet but it will be put to the test in late Feb. early March when we make a trip to Arizona from California. Overall, it went in very easily and it looks very similar to the Motorcraft OEM air filter. Only time will tell how well it performs but I have had K&N filters in all my other trucks before and they performed flawlessly. I have seen a miniscule increase in fuel economy over the past 3 or 4 tanks of fuel that I have gone through since installing it. Hopefully, it will increase a bit more.

Kirk Kettridge
Vacaville, California
Tuesday, December 26, 2017 - Part E-0644
Improved gas mileage by a couple of mpg on our last camping trip. Not many miles on our rig just yet but we were getting 9 mpg and now getting 11 mpg. The fit was good, just had to move the OAM foam over to the new filter.

Michael Wenzel
Choctaw, Oklahoma
Friday, November 24, 2017 - Part E-0644
Typical high quality, fit and value, as with all K&N products. Everything fit and worked well plus I saw/felt a noticeable increase in upper RPM power without the normal noise (and irritation) of most cold air systems. I have found over decades of using both systems that a simple change to a K&N drop in filter works best for daily street driving plus still adds power in the upper rpm area that is not much/if any less than a cold air system. I have never been dissatisfied with ANY K&N product and will continue using K&N products for all of my vehicles' filtering needs.

Rudy Johnson
Hardy, Virginia
Thursday, November 9, 2017 - Part E-0644
Great product.

Santos Chapa
Edinburg, Texas
Monday, October 30, 2017 - Part E-0644
Great product, will definitely order again.

John Lenochan
Edmond, Oklahoma