How good are Fram Airhog air filters compared to K&N and other high flow brands?
I just bought an 07 Isuzu Ascender and I'd like to improve my gas mileage (doesnt everyone?) and I was looking at drop-in filters and found a K&N for $65 and a Fram Airhog for $35. They're both washable and reusable so I'll never have to buy a filter again. I'd rather buy the lower priced filter if it's just as good or very comparable to the K&N. Will this actually help my gas mileage? I'm also looking at maybe taking the restriction out of the airbox as well. Like taking out the resonator and putting a straight PVC pipe in place. This not only improves the air flow I hear, but also makes the intake a little louder.
I drive a V6 Honda Accord Hybrid and have a 120 mile commute each day, so I pay attention to mileage and performance. I ran a K and N filter for about 2 years and I believe it provided better performance, especially above 70mph. When gas hit $4 a gallon, I switched back to the stock filter just to see if it made a difference. I gained 4 to 5 mpg with the stock filter.
There is a lot of talk on the internet about how K and Ns boost gas mileage--that's why I originally bought it. But when you think about it, modern engines automatically adjust to provide an optimal fuel/air mixture for combustion. If more air is added to the equation via a high-flow K and N filter, wouldn't the engine compensate by pumping in more fuel?