Before installing this K&N cold air intake with Amsoil air filter, I was getting 11-12 mpg while pulling my 8000 lb 30ft travel trailer.
After installing this unit, I averaged 14-15 mpg while pulling the same load.
I've noticed great mpg gains while under a load, but minimal while running dry.
Bored in school one day. Decided to make this 4" because the rolls i used couldn't go any smaller. I make the whole pipe out of a sheet of 16ga and bought a filter and a 4" to 3" coupler and stuck it on. Just gotta trim it down a bit so it doesnt rub the alternator. Now th