The K&N 33-2405 is a washable, reusable panel air filter for the 6.3L V8 Mercedes-Benz CLK63 AMG, and the manufacturer lists it for 2006 through 2008 model years. It uses four layers of cotton gauze treated with a tacking agent to trap contaminants. K&N says the design is meant to deliver higher airflow while still protecting the engine over the long run.
Compared with a disposable stock element, the appeal is reuse. The manufacturer puts the cleaning interval at about 75,000 miles of normal highway driving, and it specifies 0.85 oz (25 ml) of re-oil for each service. You clean and re-oil one filter instead of buying a new paper element at every interval, which is the main reason a CLK63 owner would pay the higher upfront price. Search terms this part targets include K&N 33-2405 CLK63 AMG drop-in filter, reusable cotton gauze air filter for CLK63 6.3 V8, and washable CLK63 AMG intake filter upgrade.
The manufacturer says the filter should be cleaned about every 75,000 miles under normal highway driving, which it equates to five years at 15,000 miles per year.
The manufacturer's listing describes a package containing one filter, and it does not clearly confirm how many are required for this application. Verify the quantity with K&N before ordering.
The manufacturer's drop-in instruction sheets for comparable K&N panel filters state that the filter is a direct replacement for the stock filter and requires no modification. The sheet specific to the 33-2405 was not located, so confirm its fit with the manufacturer if you have doubts.
This is a drop-in swap that most owners can handle in the driveway. Open the air box, remove the stock element, and seat the K&N with its cage tabs facing down into the box, then press it toward the sealing area. The manufacturer's install sheets for comparable panel filters also say to clean the sealing surfaces first, and that the air box lid's clips hold the filter in place when it is reinstalled. Because a poor seal can let unfiltered air past the element, follow the sheet's steps every time you service the filter.
