You can make a 5.3 get pretty decent fuel mileage. Don't forget, diesel is more expensive in some areas...

 

Well for a while ther until my lastest unfound issue I was the poster child of fuel milage in these trucks. I could get 26.1 if easy and averaged 22.5. I just want the power.

 

There is also a difference in fuel mileage directly related with speed.

 

Are you sure your calculator is correct? The best and I mean the very best I've ever seen is 16.7 in my 5.3. Consistantly thought I get 14.5 just daily driving. I've recently purchased a volant cold air intake and done the coolant bypass so I'm hoping to creep up to 18's.

 

We mean if you fill up all the way to the top, drive on nothing but highway for an entire tank, and fill up again. Not the every day driving.

 

Get a throttle body spacer. I used to get about 400 miles to a tank on the daily commute. I'm at 350 miles on this tank and still have 1/4 tank left. I also have 3.73's.

 

I also have 3.73's in mine. My daily cummute is 75 miles. All highway driving.

 

What kind of mods have you made??? Update your signature when you get a chance.

 

When I drive like a Grandma, I can get 22mpg with my 5.3. I also have to put a signature with my latest mods MrLM7.

 

the 26.1 was at 60 with the cruise set for 22 mile on the way to work. But Iused to average 21-22 daily driving, but being sensible, and mostly highway, and that was a full tank, multiple times. I noticed before the intake, I could get to speed and then let back on the gas pedal, loss no speed and save alot of gas.