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K&N® RU-3850 - Round Straight Air Filter

K&N® - Round Straight Universal Air Filter K&N® - Round Straight Universal Air Filter K&N® - Air Filter Overview 602x420 K&N Authorized Dealer
Item Number: 322528
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Universal Round Straight Air Filter (RU-3850) by K&N®, 1.688 " F x 3.5 " D x 10 " L. Get better performance, superior engine protection and more economical operation with a K&N Air Filter. K&N Universal Air Filters are available for just about any application.

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Universal Round Straight Air Filter (RU-3850) by K&N®, 1.688 " F x 3.5 " D x 10 " L. Get better performance, superior engine protection and more economical operation with a K&N Air Filter. K&N Universal Air Filters are available for just about any application.

K&N Round Straight Air Filter Dimensions

Dimensions of the Available K&N Round Straight Universal Air Filters:

Part # Flange Inside Dia. (F) Outside Dia. (D) Length (L) Top Style Flange Length (FL) Flange Angle (FA)
RC-08401.563" 3" 2" Metal0.625" 0 degrees
RC-08741.562" 3" 3" Metal0.625" 0 degrees
RC-08701.563" 3" 3" Metal0.625" 0 degrees
RC-11201.688" 3" 3" Metal0.625" 0 degrees
RU-25701.75" 3" 2" Rubber0.625" 0 degrees
RC-08901.813" 3" 3" Metal0.625" 0 degrees
Click Here to Check Other Dimensions
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Features:

  • Improves engine airflow
  • Increases horsepower and acceleration
  • Superior filtration without reduced airflow
  • Reduces maintenance costs
  • Washable and reusable
  • Get up to 50,000 miles between cleanings under normal driving conditions
  • Emissions legal in all States
  • Backed by K&N’s Million Mile Limited Warranty
kn air filters

K&N Universal Air Filters are constructed with ultra-strong molded pliable rubber flanges that absorb vibration and allow for secure attachment. They can also be stretched up to 1/16-inch to fit in-between sizes. The K&N filter is economical because it’s the last air filter you’ll have to buy for your car. It can be washed and reused many times, and since you can usually drive up to 50,000 miles between servicing, you won’t have to clean it very often. And every K&N filter is backed by K&N’s Million Mile Limited Warranty.

Most air filters on the market are a compromise. Many high-performance filters deliver better airflow, but sacrifice filtering ability and engine protection in the process. OEM filters, which are usually made of paper, filter adequately but at the expense of airflow. And airflow decreases as these air filters become dirty. Not so the K&N air filter. K&N air filters increase airflow without decreasing filtration ability, and the increased airflow remains consistent throughout the filter’s service interval. The secret is in the K&N filter’s construction.

kn air microfilter

K&N’s initial goal was to develop a filter that would deliver increased airflow during dirty, dusty off-road racing conditions. Increased airflow improves the efficiency of the combustion process, increasing horsepower and torque. But just increasing airflow without ensuring adequate filtration under those conditions would result in a ruined engine. K&N’s solution was a filter design consisting of 4 to 6 layers of cotton gauze sandwiched between two aluminum wire screens. The cotton is then treated with a specially formulated grade of oil that causes tackiness throughout the cotton’s microscopic strands. The resulting K&N filter not only delivers increased airflow while trapping dirt particles that could harm your engine, that level of airflow is maintained even as the filter gets dirty. The layers of oiled cotton fibers in the K&N filter trap dirt particles that are smaller than the holes in the filter media. The thickness of the layers also allows the K&N filter to trap dirt and dust on many levels, trapping more dirt without decreasing airflow. Contrast this with a paper filter that only traps dirt on its surface; as the surface area becomes clogged, the airflow rate goes down.

Brand: K&N       Part Number: RU-3850       UPC: 024844038739
bill me later K&N Air Filters

K&N® is the inventor and leading innovator of reusable cotton gauze filter technology for automotive applications. The first K&N filter was conceived for racing over 40 years ago and a performance enthusiast mindset continues today throughout all levels of the company. K&N is the sales and brand leader for performance filters, including an extensive line of factory replacement filters and performance air intake kits. The company actively promotes the environmental, economical and performance advantages of long-life reusable cotton gauze filters.

K&N® RU-3850 - Round Straight Air Filter Reviews (10)

Every Customer can leave a review about our service and the product that was purchased. In order to leave your review for your new product, please follow the link in the email you receive after completing your purchase. You can rate appearance, ease of installation, price/value and product quality.

Customers' rating: 5 OF 5
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 9
QUALITY 10
5 (5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 10
QUALITY 10
The K&N Filter
February 4, 2012 | Posted by | 2010 Cadillac CTS (Newark, NJ)

The K&N filter is a good product my car is able to breath a lot better, and it's able to accelarate a lot quicker. I also put a throttle spacer and it gave my car a 6-10 horse power.

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5 (5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 10
QUALITY 10
Awesome
February 1, 2012 | Posted by | 2008 Infiniti M45 (Grand Rapids, MI)

I have noticed that my car is running better with more performance.

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5 (5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 10
QUALITY 10
Price and Value
January 14, 2012 | Posted by | 2009 Hyundai Genesis (Milwaukee, WI)

It was easy to install and as the car has a lot of horsepower already, I was unsure of the additional power but I am happy with the outcome.

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5 (5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 10
QUALITY 10
Very Nice Filter!
January 10, 2012 | Posted by | 2006 Cadillac DTS (Ypsilanti, MI)

I have been using K&N filters for some years. They are very serviceable and in the long run I save money.

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4.5 (4.5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 4
QUALITY 10
Good Product
January 6, 2012 | Posted by | 1980 Cadillac Seville (Vernier Genève Suisse, Vernier Genève)

Very good product.

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5 (5)
APPEARANCE 10
EASE OF INSTALLATION 8
PRICE/VALUE 10
QUALITY 10
K&N Round Straight Air Filter (RU-3260)
December 29, 2011 | Posted by | (Pasadena, MD)

Filters air as required - everyone knows K&N were innovators in the filtration field. I had to do some double-checking on sizing, this is a BIG filter, and just snugly fit in my truck (03 Dodge Cummins) as I had an aftermarket air box. I just called K&N and verified that their measurements are for the ELEMENT length, not overall length, and you must include the attachment base length in your overall measurement. It's pretty straightforward on the site, but I needed to make sure because of minimal clearance. Overall, the filter works as intended, and it is able to be serviced in the future and re-used.

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5 (5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 10
QUALITY 10
K&N E Series Air Filter
December 28, 2011 | Posted by | 1988 Cadillac Allante (San Jose, CA)

Not only did it come in a timely fashion, but I was able to purchase it at the best price. Better than the factory price.

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5 (5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 10
QUALITY 10
Filters Were Awesome
December 22, 2011 | Posted by | 2011 Audi S6 (Corning, NY)

The product is awesome, direct replacement for the o.e. filter.

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5 (5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 8
QUALITY 10
Cadillac EXT
December 21, 2011 | Posted by | 2008 Cadillac Escalade (Rochester, NY)

Installs fast and K&N quality. Very nice.

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5 (5)
APPEARANCE 10
EASE OF INSTALLATION 10
PRICE/VALUE 10
QUALITY 10
K&N Filter
December 21, 2011 | Posted by | 2008 Saturn Aura (Painesville, OH)

Great product noticed the difference right away, fast service and delivery. Would highly recommend.

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K&N® RU-3850 - Round Straight Air Filter Reviews (10)
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