The easiest way for me to tell is if it has the towing mirrors.

Do you get the bigger gas tank if you have max tow?

 

Mine has the 36 gal fuel tank, as well, and does not have Max Tow.

 

I don't know if my truck is an exception. (kinda doubt it) But, it does show that you can get many of the options of the Max Tow without the "full package".

 

All 2014 ecoboost 4X4 models come with a 36 gallon tank

 

I think the earlier ones it was an option- mine definitely has the 26 gallon tank. It already hurts to fill up - can't imagine another 10 gallons!

I also wouldn't count on the tow mirrors if you are buying used. Mine has the regular mirrors but according to the window sticker, has Max Tow. I think the PO swapped them.

Here's a handy link to get your window sticker - you need your VIN and you get a PDF of it:
Ford Window Sticker

 

Actually, for the early EB models, the 36 gallon tank wasn't even an option. I think this got fixed in '12.

 

Thanks!

My sticker says 26 gallon tank, but when I put on a skid plate for my tank I needed the 36 gallon tank......... I live in CA I wonder if we have some kind of stupid tank.

 

Interesting - how much gas do you put in it? I don't think I've ever put more than 23 gallons in mine and that's when I ran it out to fumes.

 

Not sure if anyone mentioned it but the max tow was ecoboost or 6.2 only.

A 5.0 truck cant be max tow but could have some of the options selected like tbc or mirrors. HD trucks are 5.0 or eco boost but the ecoboost will have max tow by default. Confused? Me too.

All the above will be 3.73 gearing with the HD pkg getting a limited slip.

 

Well my DTE is set up for 26 gallons and the low on the gas gauge is spot on for 26 gallons.

Very confused indeed mvander.