I am looking at either getting a new grill guard or a front bumper replacement for my 07 5.9L cummins. I was just wondering if anyone has any experience with front bumper replacements and how much they effect MPG. Also wanted to get some opinions on which ones are the best. Looking at ranch hand and bodyguard right now. Live in montana so I need something that can take on Deer with no problem.

 

There was a study a while back...it can affect the mileage depending on the size, wind trapping, catching it does. I want to remember they stated anything between 0.5 and 2 mpg loss? But that study was done probably better than ten years ago.