K&N 33-2943 Washable Engine Air Filter for Select BMW Models

K&N 33-2943 is a washable, reusable replacement engine air filter listed for select BMW 635d, 520d and 535d models. Its pre-oiled, rectangular design is intended to fit the factory air box, so confirm the exact vehicle year and engine before ordering. Reuse avoids buying a new disposable filter each replacement cycle, but cleaning and re-oiling are part of ownership.

At a glance

Washable and reusable filter intended as a replacement for the factory engine air filter.
Pre-oiled for installation in the factory air box, according to the listing.
Listing specifies four layers of cotton gauze designed to trap contaminants.
Vehicle compatibility is listed for select BMW 635d, 520d and 535d years.

Price

$27.80Save 60%

Reference price: ~~$68.99~~

Price checked: Nov 14, 2026

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Pros and cons

Pros

Reusable construction can reduce the need to buy a replacement disposable filter each service interval.
Pre-oiled design is described as ready to install in the factory air box.
The listing identifies an OEM-equivalent part number for fitment cross-checking.

Cons

Unlike a disposable filter, it requires cleaning and re-oiling as part of maintenance.

Technical specifications

11 specifications

Identity
Brand	K&N
Model	33-2943
Product type	Replacement Part
Fit type	Vehicle Specific Fit
OEM part number	13717793647

Dimensions and installation
Form factor	Rectangular
Weight listed	0.77 kg

Filter and maintenance
Filter media	Multiple layers of premium cotton gauze treated with a specially-designed tacking agent
Cleaning interval claim	Engine air filter only needs cleaning every 75,000 miles under normal highway driving conditions (5 years based on the average miles driven per year of 15,000 miles)
Alternative servicing interval claim	K&N air filters can go up to 50,000 miles between cleaning, depending on your driving conditions.
Installation claim	K&N Air Filters are pre-oiled and ready to drop into your factory air box

What to know before buying

Listing details to confirm

The listed fitment spans 2007–2011 BMW 635d, 2007–2010 BMW 520d and 2004–2010 BMW 535d. Match the specific vehicle and engine to the part number before purchase. The cleaning guidance is inconsistent: one feature says every 75,000 miles under normal highway conditions, while manufacturer details say up to 50,000 miles depending on driving conditions. Warranty wording also varies between a lifetime limited warranty and a million-mile limited warranty, with limitations stated. Check applicable maintenance instructions and warranty terms.

What’s in the box

Included

1 Air Filter

Who is it for?

A good fit for

BMW owners whose exact vehicle is confirmed compatible and who prefer a washable filter over replacing a disposable one.
Drivers comfortable cleaning and re-oiling an air filter at the applicable service interval.

Less suited to

Buyers seeking a maintenance-free disposable filter.
Owners whose exact BMW year, model and engine are not confirmed against the listed fitment.

K&N 33-2943 Washable Engine Air Filter for Select BMW Models · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.7 / 5 · 102 ratings

5 stars85%85%
4 stars9%9%
3 stars2%2%
2 stars0%0%
1 star4%4%

Only aggregate ratings are available, with no customer-comment summary supplied. The rating distribution is mostly five-star, with a smaller one-star share, but it does not explain customer experiences or establish how the filter performs. Treat it as limited satisfaction context rather than evidence of specific fitment or performance outcomes.

Frequently asked questions

Which BMW models is the K&N 33-2943 listed for?

The product details list 2007–2011 BMW 635d, 2007–2010 BMW 520d and 2004–2010 BMW 535d. Confirm your exact vehicle and engine before ordering.

How often does it need cleaning?

The listing gives conflicting intervals: every 75,000 miles for normal highway conditions in one feature, and up to 50,000 miles depending on driving conditions elsewhere. Check the maintenance instructions applicable to your filter.

Is this filter reusable?

Yes. The listing describes it as washable and reusable. Cleaning and re-oiling are required, and the manufacturer specifies using suitable filter cleaner and oil.

Does it arrive ready to install?

The listing says the filter is pre-oiled and ready to drop into the factory air box. The stated package contents are one air filter.