K/N has a great hype on their filters being so good

 

Where do you live. Gas mileage will vary by region. Your mileage could be the norm for your region (Colorado, Dakotas, etc...). Also the ethanol blend of gas will contribute to the over all mileage. Someone else already asked your gear and tire set up as those weigh heavily on MPG as well.

 

I am in Texas and our gas has either 10-15% ethanol blend.

 

You will get the best gas mileage with fuel that has the least amount of ethanol - octane doesn't matter as long as it's at least 87.

 

can't find gas without ethanol. Maybe the drought will kill the corn and gas will change. Might start blending with unleaded race gas and see if that helps. Cost would go up so no dollar savings at all.