Not all modifications work the same on all vehicles. In fact, some modifications don't make an ounce of difference on certain vehicles. And some of the benefits you see on the side of boxes are not benefits that you necessarily need. For example, have you ever thought about the fact that just because an aftermarket air intake flows more air, it doesn't necessarily mean that your engine needs more air for maximum power? And though we don't want you duped by tricky marketing, we will say that generally most aftermarket air intakes will benefit the performance of your truck's powertrain. Do we think that you can gain 20 hp with an air intake on a newer vehicle? Well, we kinda doubt it. But older trucks with horrifically restrictive factory air intakes just might in fact see those horsepower improvements.
Generally, you'll be able to gain a little more throttle response, perhaps an extra mile or 2 per gallon, a little more performance sound at the engine, and maybe even be able to hold overdrive up a hill a little longer with most well-designed air intake systems. And some of the most quality air-intake systems we've seen come from AEM, so when we got under the hood of an '08 Chevy 1500, we wanted to add just a little bit of edge over a new stock Chevy 1/2-ton.