Review on 🔧 K&N Engine Air Filter 33-2409: High Performance, Premium, Washable Replacement Filter for 2007-2019 Nissan/Infiniti L4/V6/V8 (Sentra, Juke, Pulsar, Micra, Q50, Q60, Q70, QX70) by Mac Quigley

Purchased for a 2010 Nissan Rogue. After figuring out how to open the air filter holder, installation took less than a minute. It probably took longer to put a sticker on the filter cover warning mechanics not to remove the filter. This filter has been around for a long time. Why? Because the Rogue CVT tends to make the engine howl at mid to high rpm, especially when going uphill. Not far from where I live there is a stretch of road (known to cyclists) called The Wall. After installing this filter and driving up the hill at the usual speed limit of 70 km/h, my car's engine no longer makes this noise, obviously because it doesn't have to work as hard. This is such a cool filter. Accelerating on the freeway and taking pictures from a standstill are also noticeably easier. I haven't used it long enough to determine if it improves mileage, but it's pretty clear that it improves engine performance. And I've done something green by installing it: stop throwing away used filters. Highly recommended. I wish automakers would jump on the green bandwagon and put this in the factory.