I am looking for the fuel tank capacity for my truck. It's getting colder here in Western New York and want to add the correct amount of anti gel. Last winter I got the "Reduced Engine Power" message and believe I was gelling up. My truck is a 2008 Silverado 2500HD Duramax crew cab shortbed 4x4. Guage says empty and I can squeeze about 14 gallons in it. I have seen other say 20 gallons and others say 26 gallons. If I don't get a reply, to be safe, I will use a half bottle of the anti gel. Full bottle good for 50 gallons below 0 degrees.
Thank you

 

Short bed- 26 gallon-- Long bed 34 gallons.

 

Thanks. So, I still have 12 gallons in the tank when the guage says empty? Good to know. At empty, I can just barely squeeze 14 gallons in it.

 

Sound like a bad fuel level sensor in the fuel tank. Not really worth pulling the tank and fuel pump out if you are used to it reading wrong IMO.