So for anyone who was wondering.. "Does installing an air intake kit and exhaust improve MPG?"

The answer is yes. I am very consistent in driving style and have an app that calculates after every fill up.

I used to be 13 mpg city regularly, now im getting 14. not a big difference but with diesel at $4/gal I'll take it.

 

Congrats on the gain. I didn't gain any mpg when I first put my 4" exhaust on. I was to busy listening to that noise I could make.

 

I went from around 12.5 or so to around 13.8 on a consistent basis, with the 6637 and 4" turbo back. (I run through an entire tank of fuel per night, so I get to measure mileage a LOT). Once I started keeping my foot out of it a bit, I bumped up to 14-14.5 on average.

After I installed the DP Tuner I'm getting a SOLID 16, sometimes as high as 18-19 depending on what I'm doing. Keep in mind this is all mixed driving of towing, city driving, and highway.

 

I think that's going to be the reason most of use don't gain mileage with new turbo-back systems. I know when I install mine I won't be able to keep my foot out of it through tunnels.

 

I am a new guy here and just got my first diesel P/U. 1999 F 350 2X4 and I am planning to tow a three car trailer. Where may I get a DP Tuner or similar mileage enhancer? I am going to need all the help I can get as I will be putting 12 to 20K miles on in the next 3 to 6 months. I appreciate you guys that have been there, done that and got the cowboy hat! Thanks

 

When I did the 6637 and 4'' turbo back straight pipe I didnt see a single gain in MPG, I drive mostly highway between 62-65. When I got my DP I didnt see any gains in MPG either, Im past the excitement point of when I first got it too. I was gettin about 15 at best 15.9 and havent been able to break 16 yet