Im new here Im pretty sure i have 18/14 or 18/16 gallon front and rear tanks in my 91 f150 5.0 v8.... wondering now since i never take more than 18 gallons pure empty in a tank ever, and today the station charged me for 19.5 gallons for ONE front tank!!! i know i dont have a 20 gallon tank. thanks

 

Been awhile since we had one of these trucks, but I do think it was 18 and 16.

I do know that ford specs my diesel at 29, but I can put in 34 from empty.

Adrianspeeder

 

I tell ya when listin tank specs thats the tank itself and it's kinda like my gallon gas jug you put in one gallon its not full holds closer to 1 1/2 gallons if you fill a 18 gallon tank completely up its very possible to squeeze in an extra gallon countin the filling tube................

 

I've put around 33-34 gallons in mine after running it nearly dry .
I think it may be 18 and 17. I was at the parts store pricing fuel pump assemblies and the guy asked me if it was 17 or 18 gallons...I didn't know.

 

I don't know if it has the same size tanks but my '89 owners manual lists the front tank as 19 gal. and the rear as 18.2 gal.

 

I have a 1990 F150 Supercab XLT Lariat with dual tanks.
Last week I removed my front tank to fix a leak. The tank was dry empty when I put it back in.
The manual says 19 gal front and 18 gal rear tank. So I was
a little surprised when the front tank filled up to 19.492 gal at the gas station. I do not think that I overfilled either. If your front tank was completely empty, then chances are that 19.5 gal charged was about right.