The reason your are getting crap mileage is because your running at 70-80 with the AC on. Slow it down and roll the windows down and it should improve. Also, try a high quality brand of 87, like Shell, BP, or Chevron.

 

Best gas mileage, do the speed limit. Anytime you go over 1800RPM, is when your gas mileage starts getting sucked down I use to do 70 at 2000RPM in a 55, now I do 60 at like 1900RPM and my gas mileage has from from 12.5 to 14! Try accelerating a lot easier, I accelerate no higher than 1800RPM unless I need to, or want to have fun. Just lighten your foot, and do real division on your gallons and mileage.

 

Well damn, I get 300 miles with a 27 gal tank. God, my truck sucks.

 

Your problem is..

Try the speed limit sometime, you'll be amazed at the saved octane. I always get 440 - 520 miles per tank with my 35gal.

 

You don't need to turn the A/C off when you run 70, since the RPM's are high at that spped, the a/c compressor won't affect it. When you drive on the highway, do you flutter the peddle alot? I mean press and depress the accelerator alot? That will kill your gas mileage. You are def risking your fuel pump to burn out when you drive til empty since it is only sucking air and not keeping cool. Well, that my 2 cents

 

heres what you do-

dont try to stay up someones bumper in stop and go traffic
stay out of the throttle when accelerating(try setting it so that it shifts around 2k)
use a good quality fuel
use a good fuel system cleaner every once in a while to clean your fuel injectors and such
stay around the speed limit(or no more than 5 over)
control your radio volume and your anger(makes a noticeable difference)
drive it only when you need to
lose the unnecessary weight if any
use cruise control
clean the maf
clean throttle body
change spark plugs
stay up on maintenance
make sure the tires are aired up
you can get a custom tuner and a cai and exhaust but it wont help you out a whole lot to satisfy you without working on everything listed above

 

IM LISTENING TO ALL OF THIS....i drive the speed limit in town but do alot of highway driving and the speed limit is 70 where i travel....the only time i flutter the pedal is when the idiots dont move over that are in the inside lane doing less than the speed limit....i always fill up at BP or Shell or sometimes Sunoco...and the math is 380 miles 30 gallon tank topped off....i love my truck but just wondering why my gas mileage is alot less than others....maybe the o2 sensors going bad...lol

 

then do the following-
clean the maf
clean throttle body
change spark plugs(if never done yet)

if none of that helps then you need to have someone look at it or just flow with traffic. i can see it getting 18 easy if its running right as long as you stay around the speed limit and what not.

 

Gas mileage? I must have gone to the wrong forum... I meant to go to the truck forum.

 

Some of us are greedy in this economy, and that some of us that are greedy, are also not so gifted to be able to afford two vehicles, being a truck, and a economy daily driver, I happen to be one of those people who's truck is the worker, and daily driver, it brings my income in, and to keep doing so, it needs driven, which costs money for fuel, and it can hurt your money alot the more thirsty it is.

 

I bet when gas gets to $4 a gallon AGAIN, you'll respond a lil different , its almost $3 a gallon here ($2.45 and going up $.10-14 a hit!)
And its all on speculation...

Back to the OP and his driving habits, I live some what close to FLA and when you drive 70mph, which is the speed limit, you have a great chance of getting tail ended, if I set my cruise @ 75mph, which I do everyday, they blow by me and look at me like I am crazy

 

My truck is the same as yours. Leaving in 15 minutes actually to move some stuff with it. Third truck over 7 years that has had this job among other jobs.

Nope... I worked through last summer. I don't expect it to be the last at all.

I have always had to own a truck or SUV for work. I understood the cost of ownership when I bought them.

 

its the highway speed. Slow it down and it will improve. When i drive to school there is a 70mph speed limit and i put the cruise on 75(2000rpm) and i get about 14 mpg, I can barley make it to and from school on one tank, it would be cutting it very close. If i would slow it down to about 62-63 mph I can get a bit over 16 mpg. Its hard to push a big brick like a truck though the wind

 

IMO (for me, not everyone so dont flame) the "highway speed" isnt entirely accurate. My old job I had was 8 miles away, and with my 27 gallon tank, I would fill up every week at 1/8th of a tank. Now my new job is 15 miles away, and all freeway and I do 80 MPH all the way, and I still fill up every week, but above 1/4 of a tank. Im getting better mileage doing 80 down the freeway twice the distance, than doing 50 for half the distance.

That said, I fill up at 1/4 tank, and im usually at 300 miles. Its a truck, it has and will always have crappy MPG.

 

When I bought my truck I knew I was going to take a hit on gas mileage... even though I am not happy with what I get... I still love my truck. I have pretty well come to accept the fact that I am only going to get 11-13 in the city and 15-17 on the hiway. But I do try to watch my driving habits... especially with the price of gas going up.