The K&N 33-3051 is a reusable panel air filter built from layered, oiled cotton gauze in a trapezoidal shape, sized to drop into the factory airbox of the BMW 330i 2.0L. The manufacturer describes multiple layers of cotton gauze, treated with a tacking agent, that form a mesh meant to block and trap contaminants. Its real advantage over a stock paper element is reuse. The manufacturer says the filter needs cleaning only every 75,000 miles under normal highway driving. Owners who want more airflow than paper provides can clean and re-oil it rather than buying a new element each service. The filter is also sized at 10.5 x 10.25 x 1.25 inches, so confirm your airbox fits that footprint before ordering. Searchers looking for a K&N 33-3051 BMW 330i 2.0L intake filter, a washable BMW F30 330i air filter, or a 2015 2016 330i cotton gauze drop-in will find this part matches those needs.
Fitment is the main thing to verify. The manufacturer's own 330i listing includes this part number for 2015 BMW 330i 2.0L L4 gas models, and the same listing repeats for 2016, so the 2015-2016 330i 2.0L application is supported. Other catalogs show different year ranges for this number, so a VIN-based lookup with the manufacturer is still the safest step. The filter is pre-oiled, and the manufacturer lists a re-oiling amount of 1.47 oz (44 ml) for cleaning. Installation is straightforward, but the BMW airbox style matters, so the details below are important.
The manufacturer's 330i listing includes this part number for 2015 BMW 330i 2.0L L4 gas models, and the same listing covers 2016. Because other catalogs list different year ranges, confirm the application with the manufacturer's fitment lookup using your VIN before ordering.
The manufacturer states the filter needs cleaning about every 75,000 miles under normal highway driving. Drivers in dusty or stop-and-go conditions should check it more often.
The manufacturer lists a re-oiling amount of 1.47 oz (44 ml) for this filter. Use a K&N-approved filter oil and apply only what the manufacturer's spec calls for.
The 330i uses a tray-style airbox, which the manufacturer's installation hints single out. Hold the filter in place with your index fingers while sliding the cartridge into the tray so it does not drop out. If the lid is hard to close, the manufacturer suggests lubricating the back side of the tray with K&N filter grease or an equivalent. Make sure the filter sits in the groove on the lid and that the lid seats fully on the base. Forcing the clips or screws onto a misaligned lid can crack the airbox. K&N clips need a bit more pressure than a stock foam seal, so stop if the airbox bends noticeably. Keep track of all clips and screws, since they can come off during service.
