FWIW, the gauge on my 2000 S-10 is fairly accurate.  There's obviously
some safety margin built in, so you won't run out of gas as soon as it
hits "E".  However, at a computer-calculated (OHC computer) 13.6 MPG,
my gauge just dropped past the 3/4 mark with 77 miles on the tank.
Figure approx. 5.6 gallons used, so in an 18.5 Gal. tank, that's
fairly accurate.

There IS a TSB on a fuel gauge issue, with a revised part number
listed for the sender.  Mention your problem next time you have the
truck in for service (if it ever goes in) and see if they can diagnose
the problem.  That's what your warranty's for.

Oh yeah, my gauge jiggles around a bit when it's down to 1/4 tank left
and I put the truck into reverse from drive.  That's the only time the
"Low Fuel" light comes on in my truck, I usually fill at 1/4-3/8
left...

Ain't that the truth... my mom used to have a '88 250 van w/ a 318 in
it... I once let it get down to "E" when I was in HS... I had like .6
gals left in the tank as it sputtered into the gas station.  my dad's
'88 C1500 w/ a 305 he had at the time had about 10 gals left in the
tank when the gauge was on E.  my '88 K2500 w/ a 350 in it gets about
200 miles from full to 3/4, 100 miles from 3/4 to 1/2 and about 100
miles from 1/2 to E.  I've got about 6 gals to spare on mine.

-Bret

Except for my boss'!

FULL=FULL
E=150 MILES more

After a warranty sender exchange... guess they never calibrated? 500 miles
on a 37gal tank...

GMC Gremlin

"Doc" wrote:
 I get 300 miles on the

My 88 S-10 is almost like your's Doc.  Though I only get about 300 miles on
the whole tank.  The first half goes a long way, the next quarter goes
quick, and when I hit the top of the "E" line I still 2.5 gallons, though I
don't like to run it that low obviously.

Big Chris

Chevrolet may have finally fixed its erratic, non-linear gas gauges --
at least as far as the 2004 Silverado long bed is concerned.

My 1990 Scottsdale long bed suffered somewhat from erratic readings:

The gauge would stay on "full" for around 60 miles and than read
somewhat-accurately until it got down to 1/4, where it would float
between empty and 1/4 for a while. Then, it would read between 1/8 and
below empty for the next 15 to 20 miles. With the gas tank at this
level, the indicator needle would be all over the lower 1/4 range when
braking and turning. But I never ran out of gas because I always filled
the tank when the needle started to disappear behind the "E" on the
gauge. The truck had a 34 gallon tank, but I never put in more than 31
gallons of gas.

Contrast this erratic behavior with that of my 2004 Silverado:

The fuel gauge is calibrated into 16ths and the needle is very stable,
with no noticeable up and down wandering during hill climbing, turning
or stopping. After a complete fill-up, the indicator needle indicates
"full" for around 20 miles and then it begins a linear decent down to
the empty side of the gauge. Stopping and turning seems to have no
effect on the movement of the indicator needle.

When the gauge indicates "empty", I pump in around 30 to 30.5  gallons
of gas. The only problem is that I'm not sure of the exact capacity of
the gas tank, because GM has published two different specifications:

The 2004 Silverado owner's manual states on page 5-132 that the fuel
tank capacity of the long box is 36.0 gallons, but GM's pickup
literature gives a different capacity. While Chevrolet's "04 Silverado"
catalog does not state the capacity of the fuel tank, GMC's "04 Sierra"
catalog states under "Standard Technical Data" (the pages are not
numbered) that the fuel tank capacity of the long bed is 34.0 gallons.

I always get the dealer brochures for both GMC and Chevrolet trucks
because they provide a wealth of specifications which are not available
in the owner's manual. I am not always inclined to believe what is
stated in the owner's manual, because there were inaccuracies in my 1990
Chevrolet manual. For example, all of the tail light bulb specifications
were for the 1989 twist-in bulbs, when in fact, the 1990 had push-in
flashbulb types. Even the Helm manual had inaccuracies, for example, the
1990 service manual showed headlight diagrams for the 1988-89 dual-glass
headlights, when the 1990 truck had a one piece design with replaceable
bulbs.

In this particular instance, I am inclined to believe that the fuel tank
capacity is actually 36 gallons, because, on a tank of this size, there
seems to be the usual 4 gallon reserve when the gauge reads empty.
This 4 gallon reserve is typical of what I experienced with my 1990 long
bed and I have heard from others that they have had similar experiences
with full-size GM long beds. This also ties in with my experience with
the gas gauge on my 2004 Silverado. Therefore, I have tentatively
concluded the following:

Each of the 1/16th-tank increments of the gas gauge represents 2
gallons, with the remaining 4 gallons held in reserve, and therefore,
not counted. I also experimented with filling the tank when it read 1/2.
Sure enough, the tank took 16.3 gallons. Now, with Northern California
gas prices hovering around $2 per gallon, I find myself looking at the
gas gauge and computing my fuel costs by counting the 1/16th increments
down from the full side; $4 - $8 - $12 - $16 etc. When the gauge reads
"Empty", I know that it will cost me another $65, and that is
depressing.

I have had 4 or 5 chevy trucks and they all did that...they stayed on
full for 100 miles....the last 1/4 didn't meant only about 30 miles
until empty...I have gotten used to it.