poor gas mileage

#21

Bill wrote:

Quote:

I'd bet the 4wd gears are what is hurting you.
I had a 5.3l with 3.43 gears, and 70mph was 1750 to 1800 rpm.
2000 rpm was closer to 80.
I was getting closer to 20 to 21 mpg.

Mine is 4wd and I can get 19-20. 4wd makes very little difference anymore.

#22

<wmiller2502 (AT) yahoo (DOT) com> wrote

Quote:

On Dec 14, 9:11 am, azwiley1 <wiley... (AT) yahoo (DOT) com> wrote:
On Dec 13, 10:25 pm, wmiller2... (AT) yahoo (DOT) com wrote:

On Dec 13, 9:55 pm, "Ed H." <edo.h... (AT) verizon (DOT) net> wrote:

"Picasso" <Pica... (AT) gmail (DOT) com> wrote in message

news:4761d971$0$5269$9a566e8b (AT) news (DOT) aliant.net...

I have a 99 Silvy 4wd with the 5.3l and I get better milage then
that,
around 15 in town, BUT you have a crew cab and it wieghts more
then
the ext cab, plus I don't think the 05 is areodynamic. Isn't this
the
timeframe when they started changing the body style to the squared
off
front end again? When is the last time you had a service
performed?
That is going to hurt you some, dirty filter, etc..

what hte heck do you mean "Service"....
You can service whatever you want and not gain 10mpg

I'm not sure I follow your statement. The OP is asking about a
difference
of 37% max (290 miles vs. 400 miles on a 26 gallon tank), not the
almost
100% increase you suggest with a 10 mpg gain. Of course it would be
helpful
to know what the actual MPG is, rather than the range on a "tank" of
gas.

To wmiller2... (AT) yahoo (DOT) com, have you calculated your actual MPG, of do
you
just fill up when the gas gauge indicates you are low and compare how
far
you have driven since the last fill up? It may be something as
simple as
the gauge indicates low when you have several gallons left. From
your post
of MPH vs. RPM it sounds like your OD may not be engaging, which I
don't
think would account for the kind of MPG loss you claim, but real
world MPG
numbers may tell a different story.

Also, when I press the overdrive button, the enginge does not increase
in rpms like my old ford. A Gm mechanic said that is perfectly normal
for it to not increase rpms. But I don't know.How many gears should I
go through before i hit overdrive?- Hide quoted text -

- Show quoted text -

Your fuel tank is a 26 gallon tank, you have a 5.3l 1500 crew cab, 4
wheel drive. The 2008 version is EPA rated at 14 city, 19 highway.

You have not told us what rear gear you have, you have not told us
your driving habits (all city, all highway, mix), you do say you have
a light foot. You have not told us at what point you fill up,
completely empty, 1/4 tank etc. So this is the best you are going to
get for an answer.

A 26 gallon tank at 290 miles is approximately 11.5 MPG, so yes, you
seem to be a little off from what it should be.

As a comparision, with mine, with the only differences being year and
that I have the extended cab, I am getting around 350 in the city,
which puts me closer to the EPA rating.- Hide quoted text -

- Show quoted text -

I fill up when the light comes on and the miles are city and highway.
I do not know what gears I have. How can I find that out ?

There should be a tag on the differential cover that is held on by one or
two of the differential cover bolts. It'll probably be 3.73 or 4.10. If
there is no tag. you could lift the rear wheels off the ground, put the
transmission in neutral and count how many times it take to turn both wheels
in order to get the drive shaft to make one complete turn, or a dealer could
probably tell you just be running the VIN.

#23

Since you can't tell what gear you are, why don't you redneck it.
The stick on the column, put it in 1st, go, then 2nd, go, than 3rd, go, than
D, than go some more.
You should see something happen on your tach.
That will tell you if your tranny still had OD.

<wmiller2502 (AT) yahoo (DOT) com> wrote

Quote:

I have a 2005 gmc crew cab z71. I have a 26 gallon tank and I am only
getting 290 miles off of a tank of gas is this right? I know other
guys who are getting 350 to 400 miles off of their tanks. I checked
air filter and most common things. I have 60k miles on the truck and I
drive with a light foot. Thanks

#24

Quote:

I fill up when the light comes on and the miles are city and highway.
I do not know what gears I have. How can I find that out ?

Look in the glove box for the RPO options tag. It will tell you what
gears it has along with most of the options on the truck as well.
Then look at
http://www.wiu.edu/users/muwtj1/rpocodes.htm
or http://www.c2e.info/rpocodes/
to find out what they mean.

--
Steve W.
Near Cooperstown, New York

Life is not like a box of chocolates
it's more like a jar of jalapenos-
what you do today could burn your ass tomorrow!

#25

2006 1500 Z71 5.3L 3.42 gears Reg Cab around 5k on the odometer

Most of my driving is just puttering around town and I get 15.5 MPG.

Drove it 1100 miles with about 1000 lbs in the back and got 19 on the road.

I buy cheap gas, Wal*Mart, Kroger's, etc.

Karl

"Bill" <bargerw (AT) bellsouth (DOT) net> wrote

Quote:

Overdrive, that is a good point.
Can you feel it shift through all the gears into OD?

"Ed H." <edo.hart (AT) verizon (DOT) net> wrote in message
news:ebk8j.17769$k22.16588 (AT) trnddc02 (DOT) ..
My Chevy is a diesel so I can't compare it to your GMC, but comparing it
to my Dodge, which runs just below 2000 RPM at 70 MPH, it may be that the
overdrive isn't engaging, which could account for the difference. Please
note however, the overdrive on my Dodge is pretty tall (IIRC .67:1 gear
ratio).

#26

Ed H. wrote:

Quote:

I do not know what gears I have. How can I find that out ?

There should be a tag on the differential cover that is held on by one or
two of the differential cover bolts. It'll probably be 3.73 or 4.10. If
there is no tag. you could lift the rear wheels off the ground, put the
transmission in neutral and count how many times it take to turn both
wheels in order to get the drive shaft to make one complete turn, or a
dealer could probably tell you just be running the VIN.

Or look at the sticker in the glove box

G72
AXLE REAR, 2.14 RATIO

G75
AXLE REAR, 3.62 RATIO

G76
AXLE REAR, 3.36 RATIO

G90
AXLE REAR, 3.15 RATIO

G91
AXLE REAR, 3.08 RATIO

G92
AXLE REAR, 3.08 RATIO, PERFORMANCE

G93
AXLE REAR, 3.27 RATIO

G94
AXLE REAR, 3.31 RATIO

G95
AXLE REAR RATIO, ECONOMY

G96
AXLE REAR, 3.55 RATIO

G97
AXLE REAR, 2.37 RATIO

GT4 AXLE REAR, 3.73 RATIO

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poor gas mileage

4x4 Chevy/GMC Trucks 4x4 Chevy/GMC Trucks Discussions (alt.autos.4x4.chevy-trucks)

Re: poor gas mileage - 12-14-2007 , 06:30 PM

Re: poor gas mileage - 12-14-2007 , 07:36 PM

Re: poor gas mileage - 12-14-2007 , 08:45 PM

Re: poor gas mileage - 12-15-2007 , 01:29 AM

Re: poor gas mileage - 12-15-2007 , 03:42 PM

Re: poor gas mileage - 12-15-2007 , 06:20 PM