You have to take the cold air intake test results with a grain of salt. Is the air filter/filter-box sealed, or open? Most dyno tests are run with the hood open, and a large cooling fan placed in front of the vehicle. If the CAI has an open air box (no sealed lid like the GM) the cooling fan and extra air can elevate the HP/TQ output figures, but once you close the hood the filter element doesn't get as much air as when it was open, therefore not as much HP/TQ as the manufacturer claimed. CAI dyno test results with a closed air box (like the GM factory CAI) may more closely resemble real-life gains. Also, some dynamometer brands give higher readings than others, so some CAI manufacturers will use the higher reading dynos for their tests.
Another important feature of a closed air box is less resonance/drone in the cab while driving. If the hood is what seals the air box, it will pick up extra noise & vibrations, transmitting them to the firewall and cab. A sealed box also guarantees that your intake won't be sucking hot under-hood air, only the cooler outside air. Filters also tend to stay cleaner in a sealed box.
I used to run K&N CAI's but switched to the Cold Air Inductions brand on my 2012 & 2015 Camaros. Couldn't be happier. Check out the Cold Air Inductions website: https://www.coldairinductions.com/ Their 2019 Silverado/ Sierra CAI's should be out soon. The GM factory intakes are similar.
