I recently bought an 03 1500 HD and I am looking to try to get a little more with my gas mileage any advice other than the usual Intake exhaust? If thats the answer whats recomended

 

Anything that frees up flow. Cold air intake, TB spacer, headers, dual exhaust. From what I have found most headers are the same just depends on best coating for area you love in. Here in SC on the coast we use ceramic to prevent rusting as fast, cold air intake are similar, each with different features just depends what you want.TB spacers seem same, exhaust seems to be flomaster for best bang for your buck. You should really make some power fromthese on that 6.0.

 

Synthetic engine and powertrain lubes will help but it will be a very small amount. The benefits from improved lubrication are important considerations, especially if you work the truck hard.

 

Besides the normal upgrades that the other guys mentioned the other one that could help a bit is a programmer, something like the hypertech, bullydog or superchips are good ones and run about $400 bucks.