Bigger fuel tank?

[JonTiffany1]

I read on another forum where a guy ditched his OEM 26-gallon tank and got a 45-gallon tank installed on his 2003 Yukon. Since then, I haven't been able to find anywhere where such a tank existed. My problem right now is that my 26-gallon tank is filling up from 'E' with 20 gallons, and since most of my driving is city, my MPGs have been anywhere from 10.5-13.5, and I am filling up all the time it seems like (don't worry, I'm due for an oil change, ). Does anyone have any information for me, regarding either the larger capacity fuel tank OR why my 26-gallon tank has apparently lost 6 gallons somewhere? Thank you!

Jon

 

[El Capitan]

I would image a 38 gal suburban fuel tank would work. Haven't ever tried it or seen it done. Do you have an aftermarket fuel pump (oreilly, autozone, napa)? When I had an aftermarket fuel pump I noticed when my fuel light would come on and I would pump gas it would only do 18gal after oem pump with light on I pump about 22-23 gal. (by the way most cars are set-up to have a reserve capacity so unless you drive on E for a few miles you will probably not ever pump 26gal.)