Can I get a smaller gas tank for a Ford Excursion?

Yeah, I know what some of the answers are gonna be. Don't get one if you can't pay for gas. I want it for towing and it being a great winter vehicle. I will be towing a horse trailer later on and helping my family and friends with their trailer stuff. I plan on having it as long as possible. This would be my first car. I have driven a large full size SUV and a full size truck before. I don't find it intimidating and I know what they can and can't do. I can't get into smaller cars very easily because of my height and I don't feel confident in a car in case of an accident.

I have had ideas for saving money on gas like limiting how much I fill up and how much I fill it up for in a month, but I wasn't sure if it was possible for this one. I plan on not taking it for short trip in town since stop and go is bad for gas mileage. I figured that by putting in a smaller gas tank would raise mileage by less weight and fewer gallons. I don't expect it to raise much or even at all just save a little at the pump.

The Excursion I want has a V10. I tried looking for a V8 but I don't see them too often and I can't find any for sale. Gas engines only for me.

There's not going to be noticeable difference in fuel economy with a smaller fuel tank. And anyway you could simply not fill the tank the entire way and accomplish the same feat without the added expensive of procuring and having a small fuel tank installed.

" I don't expect it to raise much or even at all just save a little at the pump. "

If you're not increasing the fuel mileage at all, then explain how you're going to saving anything at all at the pump. You logic is baffling to me.

Your best of with a toyota hilux surf 3.0td, ford is a gas guzzler

As a person who has owned two excursions. You don't want a v8, that engine gets just as bad as mileage as the V10. My v10 was a 2003, and I also towed a travel trailer with it on occasions. I would get between 11-13mpg around town and upto 17mpg freeway with the 3.73 diffs. But that 17mpg was rare, usually 15mpg normally. FYI, towing an 9k pound trailer, 7.5-9mpg.
I switched to an 05 diesel. 14mpg around town and 22 freeway with 3.73 gears. FYI, on a diesel you don't need 4.30 gears or such. The 3.73 are perfect for it. Towing I would get 12mpg the same trailer.

If you are set on a gas excursion, and live in a sunny place, you can get better mileage if you do a 2wd,. If you don't tow anything or it's a very light trailer, you could change the gearing lower which is "higher", to a 3.42 gear set. This would make freeway cruising at a lower RPM.
FYI, the V8 and V10 are both modular overhead cam engines. They have a very dangerous spot in the RPM range and PCM programming that can be very dangerous if you do tow in mountains. These engines like to run above 2000RPM and have a severe flat spot in the RPM for torque. Also, if you are towing uphill for an extended period of time, the truck will upshift, causing the truck to slow to down around 30mph, if you live in the west like I do, this a recipe for disaster, because 18 wheelers don't like it when you slow down like that. That is the biggest reason getting rid of my v10 excursion. But again, if you don't tow or live in the rockies, nor plan to go into the mountains. No worries.

You don't want a smaller tank, all you'll be doing if you install a smaller tank is running our sooner and giving yourself a lower overall driving distance on a full tank
just because you can buy less at a time does not give you better mileage, less gas just means you run out sooner and have to buy more again
the weight of a few more gallons will not make any noticeable difference, maybe you would get an extra 100 years per tank, big deal and with a v10 you get the worst mileage you can get
go to any dealer and if they don't have a v8 they will order you one with a v8 from another dealership, or buy a good jeep with a v8, it can tow your trailer, gets good mileage ( even the hemi v8 will because it runs on 4 cylinders in town and only goes to 8 when you stomp on the gas or go highways speeds )

The expense of putting a smaller tank in could buy a lot of gas. First off, you don't need to fill it., second, take a big hammer and put a five gallon dent in it. There's your smaller tank.

If you are going to use an excursion for towing, trust me, you will want the largest tank possible.