Suburban Fuel Tanks

[dbdave]

I have a question for anyone with access to a parts book for the new Suburbans. The 3/4 ton Suburban has a 39 gal fuel tank. The 1/2 ton has a 31 gallon tank. Is the actual fuel tank different between the two vehicles, or is the tank the same and the vent different to only allow filling to the 31 gal level?

 

I've seen this in other vehicles where they use the same tank but use a different tank vent for different models to allow for different tank capacities. I suppose in the case of the Suburbans, the tank capacity may have something to do with the GVW with a full tank. When I look under a 1/2 ton Suburban, it looks to me that a larger tank would not fit but I realize the 3/4 ton frame rails may be different. There are just not too many 3/4 ton Suburbans around to look at so any help answering this question for me would be appreciated. It would be nice to be able to use only a different tank vent to gain the extra fuel capacity if possible.

[redvett]

The #1500 only gets the 31 gallon tank because of CAFE and carrying extra fuel isn't a plus since the larger tank reduces fuel economy. A gallon of gas weighs 6.25 lbs X 9 gal = 56.25 lbs plus the extra weight of the tank. You also will have to have the PCM calibrated for the vapor emissions monitoring. Just not worth the extra cost.