Hey guys. I love my IDI. It gets pretty decent mileage and I plan on towing often. My only problem is 17 gallons doesn't get me far. 17 gallons x 16mpgs unloaded = 272 miles if I run it clean empty. It has 2 tanks but the back tank is gummed up. What Im thinkin is if I remove the rear tank to clean it out, I had might as well install a high capacity tank! So I flipped through LMC truck and they have extra capacity GAS tanks. They also have 17 gallon DIESEL tanks. Whats the difference if any?

17 gallon original tank + 36 gallon extra capacity tank = 53 gallons
53 gallons x 16 mpgs (unloaded still) = 848 miles!
53 gallons x 12 mpgs loaded = 636 miles still!

That's 3x further! And at 3x the fuel costs!

 

I did the exact same thing you are wanting to do to my 87 and 93 7.3s. They will fit right in, but if your truck is 90 or newer. the hole and the lock ring are the same but The noches that hold the sending unit in right are in the wrong place. I used a pare of tin snips to make my 93 sending unit fit.
The longest I've gone is 700 miles, but the best i can get is 14 empty

 

From what I heard, gasser tanks are galvanized inside. Diesel tanks aren't.


Diesel apparently dissolves the galvanization, and gums up the system. Someone over on OBN has run gasser tanks on his truck for 5 years now with no problems.

And a few said diesel tanks and gas tanks have no difference.


Who to believe??? God knows.

You wanna go further per fill up? Go for it



I wanna do the same to my 94 F150 rear tank only. It's only 16 gallons (Shorty truck single tank truck). and I hate having to fill up literally every 3 days.


I want that bigger 38 gallon tank!

 

Ive run gasser tanks for a year and a half with no problems...

 

Seems like itd be worth it to me! Thanks guys!

 

the other day i put piece of galvanized pipe in a glass jar filled with diesel and capped it. I only filled it half way cause your tank will not always be full. I want to know once and for all if it really matters. You would think your filter would catch the crud though...

 

Lemme know the results!

 

Just because the filter can catch it, doesn't mean thats a good thing.... It also means you've just given your filter an excuse to plug up with crud.

I've also been running a gasser tank for several years. No problems...
Here is a key statement:
SOME gas tanks by SOME manufacturers for SOME vehicles are supposedly galvanized.

I honestly can't say what Ford did, or did not, use over the years because I've never researched it. I did research what Spectra uses on their tanks because they're available through Advance and/or Autozone and I was looking into one for my truck. Straight from their website: Spectra Premium - Fuel Tanks

From another site about Spectra ni terne coating: Note that was an MGB site hence the reference to MGB tanks.. but the ni terne explanation is the point.

The Bronco tank from Spectra is F8d and listed as 33 gallons.
There is also an F350 tank, F26E that is listed as 38 gallons, but "Exc. Diesel" which maybe just refers to it not being a factory option in the diesels?
Also, tanks appear to be the same number gas or diesel in their e-catalog (this was all looked up using 1988 as the year, looking at 7.5L (460) gas engine version diesel.