In 2000 I bought a S/D EXtended cab 7.3 5 Speed stick. 35" tires with 3.73s in 75,000 miles of driving it averaged 12 MPG ( same as the 15,000 miles it was stock). The best tank I ever saw was 16 something. Only the once & it was hauling a** to Mazatlan Mx through the mountains.

 

Hey Hest, I see that you have inquired about tuners on the V-10 a few times now. I use an SCT loaded up with custom tunes from 5Star Tuning (a site sponsor here), they really know their way around these modular motors, have excellent customer service and will work with you to get the tunes dialed in just how you want. 1999-2005 Excursion 6.8L Tuner & Programmers Archives - 5 Star Tuning
Using the Economy 87 Octane tune the trans will be in OD by 35 MPH with easy acceleration, this will help a little with the daily driver mileage if you drive with better mileage in mind. These V-10 are thirsty beasts though, so don't expect to regularly see these reported higher MPG with mixed (city/highway) daily driving. My best (back when stock) tank was 15.5 MPG and that was mostly highway with some small towns included with 6 adults onboard in hot weather, typical tanks back then (unloaded of course) were 14-ish MPG. With my current setup I'm able to get 13.5 pure highway unloaded, but my towing mileage (what we bought it for, towing not mileage!) increased from 6.5 to 9.25 MPG.
The following is snipped from a post I made earlier in the Super Duty forum discussing a guy's decision to upgrade his V-10 vs trading to a diesel. It shows the progression of my mods and their impact on our towing performance and economy.

My first hand 2V V-10 experience is as follows. Bought an '05 EX with the 2V V-10 ('05 EXs didn't get the 3V, 5R110 or coil springs ) to haul the family and son's friends to his racing events and camping. Got a 31' 9,500lb toyhauler ('04 Victory Lane 28SRV) to serve both the racing and camping needs. We take frequent trips South on I-95 from Philly to the Carolinas and GA, so I have used this same rout as my data gathering route, it's mostly flat-ish with some rolling hills in MD and VA. I log every mile and drop of gas my EX runs and do all of the calculations by hand (no Lie-O-Meter in my XLT rig) and I use an Ultra-Gauge to monitor a few OBD-II parameters and calculations.
On that route pulling the 9,500lb TH and the EX in totally stock trim (265/75R16s (31.5") and 3.73 gears) we saw 6 to 7.5 MPG towing in OD (when it would stay there, those rolling hills had it downshifting every time) at 60 to 63 MPH. Found a great deal on a set of axles already setup with 4.88 gears for $1200. With the rear axle swapped over and new 32" 18" tires and rims we made the same trip at the same weight and speeds and got 9 MPG and the trans stayed in OD without a single downshift at highway speeds the entire trip down and back. Before the next trip I added Banks headers (the rest of the exhaust is still stone stock including the cat) and got the same 9 MPG, but getting up to speed felt a little easier with the headers. Next trip saw the addition of 35" tires which dropped the effective ratio down to 4.39, that trip came in at 8.5 MPG and the acceleration was slightly slower with the reduced gearing. Next change was a set of custom tunes from 5Star (87 Economy, 87 Tow, 87 Performance, 89 Tow and 89 Performance), using the 87 Perf tune the trip netted 9 MPG again, the acceleration was back and the transmission performance improvements were a major part of that! I did try the 87 Tow tune but I didn't care for how the shift schedule worked with my style of tow driving, the Perf tune is a much better match for me.
The next big change was a new TT after the boy retired from Quarter midget racing, we didn't need the TH any more so a new 41' 11,000lb TT (Jayco Eagle Premier 338RETS) was bought. The first trip with all of the above mods still in place and the new longer heavier TT delivered the same 9 MPG. Some of these improvements may be attributed to driver evolution adjusting to take better advantage of the various mods. Subsequent trips in other directions including more hills to climb and descend have been in the 8 to 9.25 MPG range.
On a towing trip home to the Philly burbs from Charlotte NC up I-77 and I-81 (lots of big-ish Eastern mountain grades) we were a little pressed for time so I was hammering it a bit harder than usual and gas was cheaper so I was burning 89 and running the 89 Perf tune. With speeds up to 75 MPH we covered those 572 miles with a moving average speed of 59.9 MPH (pretty good considering Baltimore's Beltway traffic that evening!), the EX stayed in OD at 70 MPH on nearly every grade (as traffic allowed) at around 2500-ish RPMs and high 50% throttle openings. That trip worked out to a surprisingly good 8.25 MPG, the 89 Octane perf tune made a very noticeable improvement in seat of the pants power and it would seem efficiency too.
In my case the total cost of my gears ($1200), headers ($900) and tunes ($450) came to $2550 with me doing all of the work. These changes have really transformed my EX's towing performance from barely adequate to a good solid towing performer.
The gears made the single biggest towing, performance and economy improvement to our 2V tow rig, with the tuner second and then the headers which did improve the throttle response across the entire RPM range.
Your rig is pulling a little heavier trailer, so maybe look to regear to get to an effective 4.56-ish range vs the more popular 4.30 for V-10 tow rigs, compare your tire size to the stock size to get to the effective ratio, I use this online calculator for my numbers. 4Lo.com :: Tire Size Change, New Gear Ratio Calculator my experience was that even when the ratio was a true 4.88 the towing mileage improved nicely and the unloaded highway MPG dropped from 14.5 to 13 MPG. If you choose to go this route it can be done in steps like I did to keep the budget happier, if that's the case then I would shoot to do the gear change first.

 

Okay, one more question if you don't mind. What would you buy, all things being equal, a 2004 V-10 Eddie Bauer with 124K miles, or a 2005 6.0 diesel with 170k? The diesel is $1500 more.

 

The V10.

 

The only way you should even consider a 6.0 is with a ton of knowledge, luck of a lottery winner, and a fat wallet. Honestly.

Get a V10 or a 7.3 and enjoy driving it.

 

Been there, done that, bought the V-10 and would make the same choice again.

 

Thanks! It does have this description "It has an EGR delete kit installed and also has had the FICM replaced. " Would that change your mind?

 

********Nope!******

Just the tip of the iceberg....

 

The EGR delete is great- unless you live where they do smog checks... then you'd have to pay fines + put the truck back to stock.

 

Many of us love our 6.0L trucks, you might want to go over to the 6.0L forum, there is great information there.

 

But they are not ?? V-10 & don't look back. You have already stated your hubby don't know jack about cars & the 6.0 is an entirely nother learning curve

 

No, the gasser is a better fit for me and with the work I have done it does what I need when I need it to without any drama, gas is the best choice for me.
I don't have the level of knowledge of diesels (and the 6.0 in particular) that I would need to feel comfortable with one and I am very limited in spare time to tend to the required maintenance they should get. In my opinion a prospective diesel owner should educate themselves as much as they can prior to purchase on the particular platform they are looking at.

 

This is a loaded question. There is no such thing as "all things equal" when comparing gas and diesel. It's like saying "All things being equal, would you rather drive or fly?"

The decision is not a trivial one. It really comes down to money. You have to consider all the factors - fuel costs, maintenance costs, initial investment, and how much of your investment you're going to get back if you sell it (remember a diesel costs more, but they are also worth more). I did a fuel comparison a while back, factoring in the cost of fuel and anticipated mileage. Then the bottom fell out of the oil market and to be honest, it might have been cheaper to get a gas Ex, but pulling 9000 lbs up to 10,000 feet and not having to slow down is nice.

There are plenty of diesel owners who keep their trucks nearly stock and rarely fuss with them. Don't get the idea from these forums that owning a diesel requires constant tweaking. They don't, but they can if you enjoy that kind of thing. Not everyone does though.

 

Diesels are great for towing and I think the 6.0 is the only platform in the Excursion that gets you the 5 speed transmission. If you don't or won't be towing heavy and you have no preference for diesel then gas will probably be less problematic or finicky.

I prefer the diesel and went in understanding the 6.0 common problems which I've experienced most if not all. It pulls great, gets good fuel mileage, and sounds cool to boot, but I've put effort and $$$ into it.

7.3 is another animal that I personally don't have experience with.

I hope this information helps you make the best decision for you!

Let us know what you end up with!

 

So we went and looked at the X this afternoon. Real clean car, what worries me is the rust. All the doors have some rust. We do live in the Midwest. Is this pretty expected for a 12 year old car? We'd like it to last a minimum of 5 years. Should we just move on and search further? Proble is there are very few in our price range nearby. I'm okay with a little rust, just don't want the thing to fall apart before the engine does.
Also, how do we figure out what the tow capacity is? I entered the VIN online and it came back with this:
3.73 rear axle ratio
HD trailer towing pkg-inc: 7-wire harness, trailer brake wiring kit, towing guide, 11,000 pound capacity receiver
Wt Distributing Hitch - Max Trailer Wt. 11000, 9600 lbs 9600.0 min 11000.0 max
So is it 9600 lb or 11,000 lb?