If you're going to buy this than buy the intake. Noticed a difference with just the throttle body spacer but had a bog to it. I ordered the intake and the two together are a drastic difference better low and definitely mid range response. Haven't noticed any in gas mileage. But do buy the set. I have full after market dual exhaust and k&n filter with factory air box.
Heat shield poorly designed for filter
Intake went on without a hitch, the heat shield on the other hand, did not. The heat shield is supposed to attach to the filter and then onto the intake, with the way the shield is designed, for it to actually go on, it begins to bend the bottom of the filter due to clearance from the short rubber coupler on the filter. So I had to install the intake minus the heat shield which probably won't be very good in the long run, as the bend in the intake causes the filter to go lower into the engine