Fair warning to all on this forum. I am not a self-acknowledged expert wrench, that also holds an advanced degree in electron microscopy.

I do think that the whole fuel pump and sender unit are the same on the 26 and 36 gal. tanks. That is only my weekend wrench opinion. Better beware, as there are reel heckspurts out there.

When you set the 26 and 36 gal tanks side by side, all the electrical plugs, vapor system connections, and gas connections are identical. Additionally, the tank dimensions where these components sit are the same, such that it would be an unnecessary duplication to have two separate pump assemblies supplying the same 5.4 liter engine. Additionally, the plastic casting numbers in the pump assembly top covers, as well as many small parts, plugs, etc. are the same.

I apologise for not disassembling everything and checking for rough dimensionality with a micrometer. I just took a chance based on my crude observations, and whaddaya know....I have a functioning 36 gal tank in my little ol' 2wd.

I thought this level of weekend work was worth sharing with most on this forum.

Other critics can have at my level of competency. I will not respond further.

 

Thanks for taking the time for a write up. If you don't mind, let us know what you miles to empty says next time you fill up. In the mean time I plan to check to see if the dealer can go in and tell the ecm the corrected fuel quantity.

Thanks again.

 

When I filled up, the miles to empty gave me the same 480 miles to empty as it did before I swapped tanks. The truck doesn't know I changed tanks. Some have said that the dealer may be able to reflash so that the larger tank is acknowledged.

A little logic will say that even though the miles to empty is way off when the tank is full, as the tank empties, the miles to empty will get closer to being correct. Ultimately, when the tank is empty, it will be correct!!!

A little note: as long as miles to empty is conservative, I can live with it.

 

I'm thinking it will just show the max for at least the first 10 gallons and then will be the same as before.

 

I hope you're right, though I haven't seen where they were available in the Reg Cab Short Bed. If anyone knows different, let's hear about it.
From what was said about the differences between the 26 and 36 gal. tanks, the one point of interference for the Reg Cab would be where the frame dips down under the cab itself. Anyone know about this?

 

In the spec sheet on the Ford web site, it doesn't differentiate the reg cab models from long bed to short bed. There may be a more detailed pub somewhere else that does this.

 

Not sure on the interference issue but the order guide does show that the 26 gallon tank is the only one available with the regular cab shortbed.

 

Good find John!

 

Yeah, I bet the RC-SB is just TOO short to have the 36 gal tank fit comfortably. Oh well!
Thanks for the efforts, guys!

 

Ford learned this in the 80's. At one point they offered dual tanks on RCSB 4x4 trucks, then they stopped and all you could get was one mid tank.

Either way, I think that a 36 gallon tank is awesome. Hell, I'd be happy to see a 50 gallon tank. I could make it from Va to Maine and have gas for the week on one fill up.

 

I too LOVE fuel capacity; LOTS of it! I had a 1980 F-150 2WD RG SB w/ 2 tanks (factory option), and it spoiled me. The thing is, it's easier to put in two smaller tanks (mine were 16.5 and 19.2 gal) than one 36 gal, especially in the limited space of a RG SB truck.
And those of you crying the blues about paying for a 36 gal fillup, uhhh, who said you always have to fill it ALL the way??? It's better to have capacity and not always need it, than to not have it and sometimes need it (Today's philosophy lesson. Thank me later).

 

Just FYI, if any of you would like to look at the order guide and don't already have a copy, you can look at it here:

ProFleetSales.com - Professional Fleet Sales of Ford Cars, SUVs and Trucks!

After clicking on the link, go to the header that says "Download Center" and click on it. The order guides are listed at the bottom. When you click on "Order Guides", it will bring up all of the available Ford Order Guides and the F-150 is in there.

 

Buy that 3/4 ton Powerstroke I know you want and you could use a Titan tank.

 

I finally took a long road trip, and refilled my 36 gal tank several times at a pump. I usually fill at work, where I just fill up, no metered gallon count to judge by. Anyway, as usual, when I fill, miles to empty in the 470-480 range. I make around 150 miles before the gauge moves off full. When the 50 miles to empty light comes on, I have 5.0-5.5 gal in the tank. I can make about 600 miles running 80-85 if I run the tank low. That's a 5.4 with 3.55 axle, screw, with soft tonneau cover.

Had a couple of fills in the $115 range. The last one would have cost me about $125, except I was at work.

 

I can run that far with my 26 gal tank and EB!