Ah, fuel economy. So elusive in a 3 ton vehicle powered by large-displacement V8s programmed for hp and torque, not efficiency. Believe me, I'd love to get more than the ...

Ah, fuel economy. So elusive in a 3 ton vehicle powered by large-displacement V8s programmed for hp and torque, not efficiency. Believe me, I'd love to get more than the 11-12 mpg I'm getting with my 6.0, but I'm thinking it may be a pipe dream, for me at least. I do plan on getting the truck tuned, as well as get a tonneau cover and a throttle body spacer, but I'm running out of ideas.

It also differs from truck to truck. My old 97 Sierra half-ton saw a 2-3 mpg jump when I slapped on an American Thunder exhaust, so maybe there is hope...

So far we've covered:

Air resistance coefficient
CAIs
Programmers
Tires
Wheels
Exhaust
Ignition

But don't forget the biggest one of all:

It's how you drive. If your going to pull a boat 80mph down the highway, be happy with 8mpg.

Keep the RPM's under 2,000 and pretend there is an egg between your foot and the gas pedal....

Hey everyone,

I noticed all of these expensive ideas. I too, am in need of better gas mileage. One idea I have not seen on this list, is a tune up. For me, I have a little over 80k miles. I was curious if spending the extra money on really good spark plugs and wires is really worth it for gas mileage or any other benefit for the matter. Please, if you have any knowledge of this(IZN), let us know. Thanks

Glenn

I know we talked about tire type, but don't forget tire pressure!! Not only will properly inflated tires get you better fuel mileage, they're safer and make the tires last longer. In my experience, over half of the vehicles on the road have at least 1 tire more than 10% low...

A good tune-up will help, unless your changing new plugs for new plugs. One of my buddy's tried the tuner on his truck a 99 5.7 Z71 and he actully lost mileage. Everything stayed the same but the tuner and even in Econo. mode he lost like 2 miles to the gallon. Some things I have found that help but it could just be me is what is the quility of your fuel it seems every GM I've ever had ran differnt from fuel brand to fuel brand. I've also heard that when you fill-up could change your mileage also right before the sun comes up is the best time.

Cowboy,
I agree about the type of gas. I definitely notice a difference between brands. Generally, the better names (Shell, BP) or top tier gasoline's perform best.
Filling in the morning relates to fuel density. Some people think that the colder, denser fuel is registered differently by the pump. In other words if the fuel is more dense, you are getting more for your money. Given that there are huge underground tanks, the actual temperature variation over a short time span is minimal to nil.

Im gonna put my .02 in here as well. I know u all will think im blowing smoke but i had a good friend who owns a dealership tell me that give it one week. Set your cruise at 55 and dont drive faster unless ur on a 70mph freeway lol..you will see an increase and i have myself. I drive alot of country roads and it has worked for me.

I am going to try the tonneau cover, and I am considering the exhaust. But my truck is brand new, so I am a little reluctant to start swapping out factory stuff for aftermarket parts. Plus, I did the noisy exhaust thing in me younger days, and don't really miss the 70 mph cab drone.

I agree, koolz71. Seems that the most important improvement to make for mpg gains is the driving style- use cruise, stick with the speed limit, put an egg under that gas pedal, anticipate hills, etc...