usahoe18

Just bought '06 1500 crewcab z71 4x4 with 285x70Rx17. I got atotal off one 24 gallon tank, 340-350 miles. That averaged out to be 14.6mpg. I tripped my mpg gauge just driving on the highway and it registered basically 15mpg (and that's straight highway use). City is 13.5mpg. What's up with this?

My friend has exact same truck with 3:42 gears and he's averaging like 17mpg total. I don't know what my gear ratio is, but a lower gear would explain why my gas mileage sucks.

Any helpful hints would be nice.

BrianE

Its a truck man! Drive it or buy a rice rocket.[sm=itsok.gif]

red69

I have an 05' crew cab z71 with the 5.3 and 3.73 gears. I usually get 18-19 on the highway.

04crewcab_z71

There is absolutely no way in the world that you get 18 or 19 on the highway. You're fooling yourself. I have to agree with Brian, bad gas mileage comes with the territory, and if you can't get used to it, you should probably not drive a truck. But seriously do put a cold air intake on there, that will help a bit, and then get a tuner if you can get the money together; that will help too. But anyway you look at it, with all that equipment, you will never have 20 mpg, and probably not even 19.

Old Coot

I believe he could very well get 18 to 19 on the highway. I have an 07 with the 6.0 with 3.73 gears and 265-70 tires and live in a rural area. We have no highway driving except about 12 miles each way a couple of times. The computer average since we got the truck is 14.5 mpg. It only has 800 miles so it isn't even broken in yet. My 03 with the 5.3 averaged 15.2 mpg. Keeping your foot out of it helps.

ashekicker

06 LS 4x4, 4.8L crew cab. 19 highway. Of course when u turn on the a/c it drops. But highway driving in the mountain state showed 19. K&N 77 intake, magna flow exhaust.

usahoe18

Do ya'll think it's the 285 tires on mine? I never expected it to get 13mpg in the city. And definetely not 15 on the highway. I never "romp" on it either, just feather the gas. Maybe I'll switch to 89 octane, or maybe even 93. Is that worth the extra money?

Just for thought, my friend with the exact same truck with 3:42 gears got 10mpg pulling his 24ft. flat bottom boat 3.5 hrs to the beach this past weekend.

How can I find what kind of gears are in mine? I don't have the sticker in the window anymore which should tell you.

Old Coot

Look inside your glove box and you'll find a service parts list. That list the options on your truck. As near as I can tell the 06 should be:
3:42 ---GU6
3:73---GT4-F F may or may not be there but it shows that for the 2006.
4:11---GT5
This is my parts list and shows a GT4 on a 07. That is a 3:73.

kcb37

I think your milage could be better. Part of it may be that it isn't broken in yet. It may just be your gears. If the sticker dosen't help you can call the parts department at a dealership and give them your vin, they should be able to tell you what you have.
I also have a 96 Silverado 1/2 ton, (mine is 2wd) with a vortec 350, I get around 18 on the highway. Averaging 70, 75. A free flowing exhaust and an intake kit (air filter and tube to the intake manifold) will help. It may not be a lot but it does help some.

hunt4game29

I have a 2005 silverado z-71 and with 265 70 r17 i was getting 18 mpg on the highway and even 21.3 one time on the highway. But i put 285 70 r17 on and now im getting about two or three miles less so yes it is the tires that is getting you less mileage. Thanks