Review on K&N Cold Air Intake Kit for 2001-2007 Chevy/GMC Heavy Duty 6.0L V8 (Silverado 2500, Silverado 3500, Sierra 2500, Sierra 3500), 57-3031-1 - Enhanced Performance and Increased Horsepower by Joseph Stone

I was hoping to improve gas mileage when towing my 23ft RV, nothing changed but it worked as advertised, my RPM dropped 300-400rpm while towing my RV. When going up a steep hill, my 2005 2500 Suburban doesn't go from 2100 rpm to 4200 rpm. It ramps up from 2100 to 2400. It's in tow/haul mode, so revs down and helps with shifting and power. My 2005 Suburb has 177,000 miles on it. Last June I completely rebuilt the transmission as preventative maintenance. To be honest he didn't say it would increase mileage, he said it could increase mileage. When the camper is not towed it normally runs at 2100 rpm at 60 mph, now 1800 rpm. My engine wears out less.