Stock Air Flow vs. High Performance Cold Air Intake Systems
Most fuel injected vehicles don't have space to mount an air filter right on top of the engine like they're positioned in carbureted cars and trucks. So engineers find another spot under the hood to tuck the air filter, and then use tubing to route the air that passes through the tube on to the engine.
Stock tubing is most often designed to make the air movement quiet, without a lot of regard to optimum airflow, but less air to the engine means less engine power. One solution -- a cold air intake system that replaces the stock filter and tubing with parts designed to get more air into the engine. More air in, more power out.
Cold air intake systems usually have a box or divider that separates the air filter from the heat of the engine and allows the system to capture cooler air coming through the grill or fender. That's a better option than grabbing the warm air under the hood, because the colder the air the more dense it is -- and dense air lets the fuel injectors supply more fuel to the engine to enhance horsepower.
Installation took about an hour and a half, and I think anyone with a few basic mechanical skills can bolt it on just as quickly.
Designs vary, but K&N makes its cone shaped, free-flow filters as large as they can be for each vehicle in order to allow maximum airflow.
The tubing that takes air from the filter to the engine is not metallic, so it tends to stay cooler than metal versions. K&N thinks the material also tones down the sound of the air as it travels through the tube.
After you install the cold air intake, you will hear the air as it enters the filter. At low throttle, you'll hear a slight whistle. On hard acceleration, you'll hear more of a roaring sound. I don't find it loud or offensive, and if you're looking for more power in your truck, you probably won't mind the sound at all; but consider the sound if you prefer a very quiet ride.
How the Unit Performed
I noticed an increase in power with the trailer empty, but it was even more obvious after I picked up the car and started pulling steeper and longer hills. The truck performed much better on hills with the system installed than it ever did before installation.
I don't have a machine to test power, but saw evidence of the boost in the way the truck operated. In many instances the transmission didn't need to downshift to maintain vehicle speed on a grade or hill. Overall, downshifts happened a whole lot less frequently.
K&N doesn't claim that you'll get better mileage when you install their systems, but my gas mileage has gone up about a mile per gallon in both city and highway driving. An increase in power that takes less gas to produce -- that's fine by me.
Kit Maintenance & Guarantee
The company sells replacement air filters for most vehicles, but don't expect a significant horsepower boost from just a filter. A replacement filter has to fit into the existing (smaller) air box and the truck still has less efficient factory air routing tubes beyond the filter.
K&N has been around for a number of years and has a reputation for producing quality products. They came through on this accessory, from the well written instructions to the system's appearance to its actual performance.