Jul 16, 2008 | , and for good reason. Cold air intakes offer increased performance, improved gas mileage, go-fast looks, and a great sound. These kits work because they increase air flow into the engine while also making an effort to ensure the intake air is as cool as possible. Unfortunately, while they do work, cold air intake kits cost $300-$400.For years, K&N has been offering a less expensive alternative to cold air intake kits, specifically, a high-performance air filter. K&N says that their high-flow air filters significantly increase air flow and therefore offer many of the same benefits as more expensive full-fledged intake kits. We decided to check that claim, and here’s what we came up with:1. While there was no significant gain in measured horsepower (all our test runs were within normal hp variance), there was a noticeable improvement in throttle response and engine performance at cold start.2. Get your wallet ready – if you don’t already have a K&N air filter (or an air intake kit), buy one now.

We noticed more than a 0.50 average improvement in mpg on our test vehicle over the course of 2 weeks and about 800 miles. Before we added the K&N, our test truck averaged 14.3 mpg. After the filter was added, the test vehicle averaged 14.9 mpg. That means that over the course of our test we saved 2.3 gallons of gas. Put another way – spending $50 on a K&N air filter that improves your mpg 0.60 will pay for itself in about 5,000 miles – if not sooner. If you extrapolate out to 100k miles, our test results show that the K&N performance air filter will save you about 280 gallons of gas. That’s about $1,100 in gas savings!3. K&N Million Mile Warranty. If the gas mileage improvement isn’t enough incentive for you to buy a K&N air filter, here’s another. K&N’s performance air filter comes with a 1,000,000 mile warranty. As long as you clean it (every 25k-50k miles), it will last forever. The factory air filter (made from paper that is more restrictive than the cotton gauze K&N design) should be replaced every 15k-30k miles, at a cost of $20 per filter.

The cleaning process does require you to buy a $20 re-charger kit, but even if you pay $60 for the K&N filter and $20 for the cleaning kit, you still break even after replacing four factory air filters (which can take 60k-120k miles, depending on how dirty your filter gets). Not to mention the gas savings…We installed the K&N performance air filter in a 2007 Toyota Tundra double cab with the 5.7L V8 (above). Thanks to Larry for providing his truck and allowing us to test K&N’s air filter.4. panasonic air purifier modelThere are a few rumors out their that adding a K&N air filter (or similar) to your vehicle will ruin your mass air flow (MAF) sensor. clean air europe cafe programmeSome of these rumors are true – if you clean and then grossly over-oil your K&N air filter, the excess oil will enter your air intake and could foul your sensor. best air conditioning coil cleaner

As long as you’re careful, you won’t over-oil your filter when you clean it. K&N has a decent explanation of why their air filters can’t hurt your truck, but the best explanation follows. TRD also sells a cotton-gauze performance air filter just like the K&N filter – they also offer a cleaning kit, just like K&N. Since TRD sells a nearly identical part for a new Toyota, you’ve got nothing to worry about.5. There are a few companies that sell performance air filters similar to K&N – aFe, TRD, and FRAM might be the best known. Since we haven’t tested any other performance cotton-gauze air filters, we can’t say for sure that these other brands offer the same benefits. But it’s a pretty safe bet that they do. We would definitely recommend the K&N air filter over the TRD unit simply because of the cost. As for the rest, since there’s no substantial price difference, there’s no reason not to choose the K&N.Our test of the K&N air filter showed an average 0.6 mpg improvement.

Extrapolated to 100k miles of driving, that works out to about $1100 in gas savings (assuming gas costs $4 per gallon).Bottom line: If you like fuel economy and better throttle response, buy a K&N performance air filter. They cost about $50 now, and between the million mile warranty and the gas savings (we calculated $1,100 dollars worth over the course of 100k miles), it’s a no-brainer. (where shipping is always free), Auto Parts Warehouse (sometimes offering a 10% discount on K&N parts), and 4 Wheel Parts. Between the three, you should be able to find the best price…just make sure to include the shipping cost into the final figure. Some online parts sellers discount the part but then add on $10-$20 in shipping and handling charges, so watch out.A few months ago I was contacted by RabbitAir to see if I would be interested in reviewing their RabbitAir , Minus A2 Ultra Quiet HEPA Air Purifier.  I was thrilled and quickly agreed and was sent the Cherry Blossom design.  The Minus A2 is the only air purifier designed to either stand alone or be mounted on the wall.

Floor stand is included with unit and can be easily removed for wall-mount.  With a 5 years warranty on parts and labor and 24/7 technical support, the MinusA2 is one of the highest quality air purifiers you can find. Craftsmanship is carefully monitored in every step of the manufacturing process, with all major components, including the motor, filters, and air quality sensors manufactured in Korea.  You can customize your MinusA2 air purifier by choosing from a variety of custom filters that will benefit you most. You have the choice of Germ Defense, Pet Allergy, Toxin Absorber or Odor Remover.  The MinusA2 SPA-700A air purifier will filter all of the air in a room up to 700 sq. ft. (or 815 sq. ft. for the SPA-780A) twice in an hour on the turbo setting.  The heart of this air purifier is the Brushless Direct Current Motor, an innovative motor with inverter control that offers 5 different speeds of operation. When operating at low speed, the air purifier’s motor barely makes a sound.  

Only consumes 7 Watts at silent speed. Inlet: Indoor air is drawn through the filters 360 degrees around the front panel. Outlet: Clean air is expelled from the back of the unit in an upward direction towards the room. Power Cord Length: 9.33 ft. Normal Residential Use (2 air changes per hour): SPA-700A : 700 sq. ft. SPA-780A : 815 sq. ft. Allergy Sufferer (4 air changes per hour): SPA-700A : 350 sq. ft. SPA-780A : 408 sq. ft. SPA-700A : 7 to 47 watts SPA-780A : 7 to 61 watts SPA-700A : 20.8 to 45.6 dBA SPA-780A : 25.6 to 51.3 dBA SPA-700A:     201     200     193 SPA-780A:     208     200     193 Support: 24/7 Technical Support Power Requirements: 120V AC 60 Hz This Air Purifier was so user-friendly and easy to set up.  It had a quick start guide and all the filters were individually wrapped with a “Hello” sticker explaining exactly what they were and how to place them back when unwrapped.