If you wanna get picky, get new mirrors, dump your tailgate, and rear bench seat assuming it's an ECSB. Have Justin write you a new tune that focus' on economy. But that lift is what is killing you. If you were to drop it you would gain I'm guessing 4mpg at least. I had a stock CCSB that was dropped and was getting 20mpg on fwy stretches. Also swap out for some 3.23 gears.

 

I have 37's and the best I have seen was 16 on the highway at around 60mph. With mixed driving I usuaslly average 13mpg. Alot of it has to do with driving habbits. I second with the daily driver vehicle idea. When I want gas milage, thats what the motorcycel is for.

 

I only drive under 15k miles a year so I don't mind the bad gas mileage. I am doing performance mods and was trying to see what to do next. So no performance mod I am going to do, is going to change my gas mileage?

 

Haha. They almost all change it....for the worse.

 

You only drive under 15,000 miles per year?!?!? Only? There were good examples of "performance mods" (performance being a relative term which in this thread seems to be the efficiency of your truck as opposed to the acceleration prowess it retains) posted by various members previously in the thread that will show some mileage gain. Without conservative / consistent acceleration and steady reasonable cruising speeds, you will be hard pressed to realize true MPG gains.

 

What would be the difference in the economy tune and the one I have? My truck has plenty of power being a RCSB.

 

4x4 - mpg killer
3" lift - mpg killer
33s - mpg killer
3.73 - mpg killer

This is not what you asked for, but if you are so concerned about gas mileage, you need to 1) get rid of your truck, 2) mod the above listing for better mileage, 3) stop worrying about it.

Now, you asked about 'performance mods that would help mpg'. Wow, not too many of those that I can think of.

1) E-fans definitely fall into that category. I personally see a increase of 2mpg. If you see 1mpg, with efans, you should fell lucky. Your truck is a heavy beast.

2) Weight. Reduce it. Do it however you can, just reduce the weight of your truck. You will see quicker acceleration and better mileage, if driven properly.

3) Right foot. This is not a performance mod, but it will increase mpg. Learn how to drive to improve mileage. Do a search on hypermiling to get some tips.

 

I am not going to change anything on the truck, except motor/drivetrain mods. Stop telling me to take my lift and tires off. That is not an option. I have a lifted 4x4 truck, so obviously I wasn't expecting 20mpg. I was just looking for ways to improve my gas mileage, and maybe make it a little quicker. So after that, should I notice an increase with long tube headers or e-fans?

 

Put the stock exhaust back on and I bet you'll see a big increase in MPG.

 

Why change back to stock? I thought free flowing exhaust helps mpg?