Yah, i reset the HUD everytime I fill up, also I like to only fill up about 20 bucks a time to keep it about half a tank for a bit less of weight and i use to top off the tank all the time when i was getting BETTER mpg.

Replace the air cleaner and clean the TB.



BTW<------ He never sent me my 10 plugs! He didn't want to be liable for anything that happened to my truck!......What an ***!......I would have done the test accurately! Everyone knows it, but he didn't give me the time of day, wonder why.....LMFAO

if you run the tank low you could very possibly have picked up some dirt and are clogging the fuel filter, it is better for the pump and fuel system to keep that tank full (anything below 1/4 tank is to be avoided IMO) you could try a bottle of fuel injector cleaner to see if that helps clean anything out of the system. the favorite on this board is sea foam.

and also filling the tank is the only way to get an accurate read on your gas mileage.

Well that was your first problem!


You have to fill up every time! Then do the math with gallons used and mileage traveled. Then divide gallons into mileage and write it down for at least 1 month. Replace the plugs and do it again with the same exact mileage and conditions!

This is an adequate test, however you are having issues with your truck and trying a test isn't going to prove anything. You need to fix the issues first before you try anything and I don't think those plugs are helping you in any way.

want to report that i went on a 20mile each way drive last night, doing about 70-80 and im happy to say I was averging about 16.2mpg

So I should restate myself, Something, im assuming the plugs hleped with my gas mileage as when I use to get the 14mpg, that was alot of freeway mileage, I really havent done ANY open road driving in the last 2yrs so im happy

also let me clarify i am still getting these results off the HUD...

The Over Head display is incorrect. You must do the fuel to mileage math.


Also, if you have oversized tires or anything that could through off the test, you have to include that.

In my old fully built 5.9L got 15.8 on the freeway at those speeds and I had that motor built and drive system to the nuts! ($10,000 bucks worth) That was the actual mileage off the pump.