Reviewed By jeff l (POTTSTOWN, PA) Reviewed for a 2003 GMC Envoy —8/22/2013 10:56 AM
I purchased this for my 2003 Envoy XL 4.2L V6 for towing mostly. I also have a K+N cold air intake. My wife and I have noticed a difference in shifting gears, lower RPM's in regular driving and towing, more power where it needs to be, but have not seen a drastic change in fuel economy. Have only had it installed now for 3 weeks. I would certainly recommend this to anyone.