Just owned this for over a month, seeing a discrepency between advertised fuel capacity and real world. When my Sierra's fuel light came on, it was close to the stated capacity of 26gallon give or take 2gallons. When I have filled the Burb, after the light comes on, it has been around 24-25 gallons, where is the other 5-6gallons? Is this a built in reserve?
Does it have a 31 gallon tank or just 26 gallons? Any thoughts?

 

pretty sure around 26 gallons that is the most I have put in with the low fuel indicator on but there may be a larger tank in some - check your glove box for the codes or get your VIN and go to this site
it will list every option that is on your vehicle
Comprehensive Chevrolet, Saturn, GMC, Hummer, Cadillac, Buick, Oldsmobile, Pontiac, Geo, Dodge, Plymouth, Jeep, Chrysler, Ford, Lincoln, Mercury, Mazda Truck, Mercedes VIN Decoder

 

i don't believe the capacity of the tank as listed includes the hoses... so you may be 1-2 gallons off at fill.

 

Should be a 31 gallon tank. I tend to fill based on the odometer as the low fuel light comes on too soon. Put 28.5 gallons in last night. Too much $$$$$$

 

31 gallons is what is advertised

26 gallons for tahoe

 

Since the fuel pump is cooled by the fuel in the tank, it's not a good idea to consistently run the tank below about 1/4 full.

 

The indicator is well only an indicator... it can be influenced by the incline of the vehicle...
I just replaced the fuel pump in the little woman's mini van this week and yes the fuel does cool the pump motor but it was interesting to see how the body of the pump fills up with gas to keep that fuel around the motor housing and keep a reserve of fuel at its disposal when the tank is near empty and on an incline...
Even after pulling the pump assembly out it held a good quart or more of fuel...

She was having hard starting issues( multiple cranks to get started) and a quick check of the fuel pressure showed it was in the 40s psi and very unsteady and dropped to 0 when the engine shut off... the new pump read a solid unwavering 60psi and 56psi with engine off....
Very handy tool to have -> Amazon.com: Actron CP7838 Professional Fuel Pressure Tester: Automotive

 

Curious, what damage would that cause? As I have been driving to empty for 30+ years. Only had to replace a fuel pump once and that was under warranty as the Jeep only had 11,000 miles on it.

 

Its more of a rule of thumb so to speak,
Heat can kill the pump prematurely, when its 90 degrees out side the heat coming off of the asphalt can be 120 degrees or higher, the fuel pump is less then 20 inches from that heat for extended periods of time....

The pump creates its own heat while running, ambient temps can compound impact the longevity of the pump....

 

So basically the fuel gauge is most likely "off" to help protect the fuel pump. So GM/Chevy designed a flawed system with 3 to 5 gallons of unuseable fuel. Not such a big deal driving around town, but for towing and trips would like to be able to take advantage of those extra 3 to 4 gallons without having the tank on "empty" and still have 2 gallons to help cool the pump. Will see how it does on a long trip, SC to NY in a couple of weeks.
Thanks for your replies and information on fuel pump cooling.