Suburban / Blazer fuel tank dimension differences

[Frankenchevy]

I’m looking at adding a suburban tank to another vehicle. Between the 25/31/40 gallon variants, where do the dimensions grow? Is it length or is it depth? If its depth is it downward or upward? I can’t imagine it’s upward. Lastly, does anyone have different sizes that they can measure? Mostly interested in depth for axle clearance purposes.

 

[bucket]

25/31 tanks share the same footprint, but the 31 gal tank is deeper. The 40 gal tank is longer overall, but I don't recall if it's deeper than the 31gal.

 

[Frankenchevy]

Sounds like the 25 gallon offers the most clearance to the rear axle then, which makes sense being the smallest.

I’m kicking around the idea of using one as an auxiliary tank in my older Cummins where the spare tire used to live.

There’s a company that makes spare tire shaped tanks, but they want about $2000 for one.

The factory tank is 35 gallons. With a 25 aux, I’d be up to 60. Which is more than the factory 50 that’s in the newer Cummins. The newer truck has a 1000mi range on the highway, but it’s on really mild A/Ts.

I’m curious what my older one with a 6 speed manual will get on the highway with a 1,500lb camper in the bed on M/Ts. I’m shooting for 15mpg, which is what it got towing our travel trailer to Utah and back.

 

[idahovette]

@Frankenchevy wash it .....it'll be lighter!!!!!....been a while