i just added a k&n filter to my 4.2 now they say it improves gas milage and gives more horse so how much more horse and gas mil will i get out of it the thing cost 60 bucks so will it pay itself of

 

If you got a drop in, you might get 2-5 horsepower out of it. Not enough to notice. And as far as mpg....I wouldn't count on getting anything out of it. If your lucky you might get about .5mpg.

 

I disagree with this. I definitely noticed better throttle response and acceleration. The engine pulls alot harder when I put my foot in it. After 4 months of keeping a VERY close eye on mileage I average about 1-2 days extra on a fill driving the same mileage each week (+-). This has worked out to about 3 mpg improvement city and around 5 mpg highway.

This may not sound like much but with gas sitting at $4/gallon Cdn I'll take whatever I can get.

 

I observed absolutely no improvement in mileage or performance with a drop-in K&N filter.

In the long run, it may save you money on filter replacements.

 

I tried the K&N filter,then threw it away!The silicon (dirt) in my UOA was off the charts with it in there.I put the factory filter back in,had another UOA done,hardly a spec of silicon!