When I posted a topic in February about installing a cold air intake made out of spare record player parts several questions were brought up about improvements in fuel mileage along with power increases. With now more than 4600 miles on this part I continue to find reasons pull through the gears in city driving and visit the red line when getting onto the highway. City mileage even with aggressive driving returns consistent 26-28 mpg. Highway trips have provided 33.7 mpg while maintaining 73 mph where allowed. I can't verify a horsepower increase but I would realistically say that 5-6 hp and 3-5 ftlbs of torque is the net result. The biggest benefit is that the torque band is now lower in the rpm range and pulls strong from 2200 and fades at 6250 rpm. I read all the post about removing the air box resonator tube for increased power, and can agree there is an improvement with this mod, however this modification can be improved by leaving the tube in place but cutting out the front panel of the resonator box so it is open from the front. For those of you with SEL's, air passing around the driving light will provide a cool air charge up into the filter box. Those with S and SE models you can remove the black plastic driving light plug and either perforate or remove the flat back area to allow air to pass through and directly feed the modified air box resonator. I'm still suprised that no one has purchased the Cold Air Intake that is being sold on E-bay for the I4, unless something is wrong with that piece. I do know that my homemade system works extremely well with no codes to date.