32+ MPG Ford Excursion 4x4 Limited
 

Greetings everyone!

I just found this site while researching a new project car and thought I'd join up. (Looking at putting a turbo diesel into a 1966 Austin Mini Cooper.)

I've got a few more maintenance mods to make on my wife's Excursion, but between the new transmission and bigger injectors, shortly before our Christmas trip to Walt Disney World; it was a great discovery into how beneficial the upgrades were. With the fast traffic flow on the way over from North Texas, we averaged (all highway) ~26 MPG @ 70-75MPH (~2050-2300 RPM). We were able to stick to the speed limit on the way back and got ~32 MPG @ 60-65MPH (~1700-1900 RPM). City (suburban) driving is down around 18-20 MPG.

At almost 200K Miles, all of my focus lately has been on replacing / upgrading the brakes and suspension components. So, once I have that out of the way, I plan on adding a regulated return fuel system upgrade, which should make some significant improvements to engine noise, throttle response, and minor economy.

In case you’re wondering, in general, Excursions tend to have much better economy results after tuning than do F250s.

List of mods:
2001 Excursion 4x4 Limited, 7.3L PSD
-High Pressure Oil Rail Crossover Hose
-MBRP 4" Turbo Back with 3" down pipe
-4 possition Diesel Innovations Performance Chip
-International HO Performance Injectors
-ATS Transmission
Everything done by dieselinnovations.com

http://www.smugmug.com/gallery/7259288_n2R4C

Cheers!

That's great for such a big vehicle! Makes me really, really wish my Jeep was diesel... 20-21 mpg highway (60mph) in a vehicle half the size seems downright horrible in comparison.

Thanks, it was an unexpected nicety.

Back when I drove a Jeep Liberty with the V6 Gasser, I considered replacing it with the Buick 231 Turbo that I have sitting out in my garage, ATM. In my dad's T-Type, that engine pulled roughly 22/26... Of course, the CRD is a good option that can drop in without too much trouble.

What kind of RPMs do you turn at said speed? What is your axel ratio? Auto or manual?

Good numbers...almost too good. :?

It's the standard 3.73/Auto combination...

I don't recall her exact RPMs (See update).

As a standard rule, anything I replace on the truck gets upgraded to a better engineered option (if available) and after getting a ridiculous quote from the stealership after one of her injectors fried, we opted for a set of +75HP International injectors. The old stock torque converter gave up the ghost at around 160K miles - probably due to the added power of the new injectors and since Ford isn't known for rock solid transmissions, we went with Diesel Innovation's remanufactured unit with heavy duty TC.

Not all large PSD powered vehicles gain this much, we got lucky. Our numbers are good and sustainable after having logged and done the math, the OBD Display is within a 10th of 1mpg accurate. It was quite a supprise after having filled up for the return drive from FL that the DTE display stayed at 999 for over 2 hours. At first, I thought something was broken. :D

Can you quantify your modifications?
Like such and such a modification yeilded a certain mpg benefit?

I wish I had been more involved from the beginning, but the Excursion was my introduction to the Ford PSD. So, I'll give you a list of the MODs applied and an economy SWAG.

Purchased it with roughly 106K on the clock. Cty/Hwy 14/23 (stock)

The first MODs installed were the Sonnax shift kit, aFe Stage 1 intake, MBRP 3" down pipe to 4" back exhaust, and 4 position performance chip from DI. Cty/Hwy 15/25

After she lost the #8 injector, we added a set of new AC high totque injectors, high pressure oil rail cross over to help address the fuel starvation issues on the #6&8 cylinders, and all new programming for the chip to deal with the new injectors. Cty/Hwy 16/26+ (Hwy is tough to say because most of her driving was within 5 miles of our house. So to be honest, the only way I calculated at this time was to reset the computer while making fairly short runs on the Hwy)

Because of the TC taking a powder, we went to the transmission and HD TC within the first two weeks of doing the previous mod. It was after this that I had a chance to re-certify the accuracy of the OBD display...

I can say this too, the stock TC was slipping big time!

Thanks, especially for the details!
I thought those were lock up torque converters?
The "all new programming for the chip to deal with the new injectors" did you get that done on a dyno or just a mail order tune?
Why is it that Excursions tend to get better MPG after tuning than the F250's? I thought the motors were identicle?

Yep, they're lock-up torque converters... However, the added wear (previous owner never serviced it properly) plus increased torque from tuning can cause the TC to cheese out internally (various things can fail, e.g. clutch, turbine, impeller, etc (actually, malfunctioning TCs can result it massive fuel consumption issues...), which will result in slippage or catastrophic failure. If memory serves me correctly, my old transmission was also having trouble shifting out of (or into?) 3rd (per the codes). Overheating the trans fluid will cause the ..peller fins to warp and eventually frag out.

Fortunately, I'm only a few miles from DI's headquarters here in Houston and they simply pulled the module and re-flashed it with a program that covered my mod combination. Had I mail ordered it from them; I would have had to arrange either a cross-ship or else be down for a few days. It would probably run on the stock ECM, but would have been very rough - I assume it may have perhaps gone into "limp mode". Since the injectors are all mechanical expect for the firing mechanism, timing is a key factor.

Yes, same engine, but slightly different function/logic in the wiring harness. One example that I'm painfully aware of is the Excursions like to fire the glow plugs during normal operation, whereas the pickups only fire them to aid in start. (Twice) in my case, this resulted in my under valve cover harness all the way back to the glow plug control module frying itself out - thanks to Ford for having engineered the glow plug wire using a light gauge wire. (on my list of things to do is to mod the harness with a heavier wire (have heard of a mythical repair kit, but haven’t found it yet)) This alone isn't enough to make that much of a difference... “The Wizard” at DI told me that his customers tend to report higher numbers on Excursions, but the reasons aren’t exactly clear (most of his clientele aren’t exactly looking for economy). After all, Excursions are quite a bit heavier than their pay-loading cousins.

My F250 has slightly more mods than the Excursion (I have the aFe stage II intake, the regulated fuel system, and more aggressive programming) and I'm only seeing 14/26 at best. My wife has mastered the driving habit, whereas my lead foot gets in the way. ;) We’ll see how it fairs after I upgrade the tranny and injectors – have to wait for the current one(s) to fail. And this will have to wait until after I get my Austin Cooper up and running, hopefully with a TDI under the hood.

I added the URL to my project page - its work in progress and I've got a real job to attend to.

I call bs. An excursion won't get 32mpg if you drive it off a cliff. Not with a tuner,injectors or hypermileing. Just because you post a picture of the lying trip computer is not proof.
Maybe if you had a video of a scan gauge while driving I would believe it but your claims are so far above anything I've gotten and everything I've ever even heard of leads me to say...BS!

It's hard to believe even though it's a diesel. I just read up on your excursion and people with the same diesel are reporting 16-17mpg at 70mph so your truck gets 100% over that

While the claims may stretch the limits of credibility, maybe YOU should look at Diesel Daves Mileage in a similar size-weight truck. Close to 50 MPG. I'm not saying it is true or false just that we should see what has been done and the driving technique used before calling someone a liar.

regards
Mech

My buddy has a f350 2010(i think) w/ a diesiel and 4x4. also a hug bumber guard and a tool box.
Hed has a aftermarket af and tail pipe mod.
I worked w/ him for a month at his ranch and he got 20-22mpg on a tank w/ 70% freeway driving (very little ranch driving)
I'm just having a hard time w/ the 70mph.........and the 32mpg in the same sentence....

The way I read it was 26mpg @70 not 32mpg at 70. I believe it's possible. I used to have a mercedes diesel and would get 48mpg pulling a 4000lbs trailer at 65mph.

my bad..stand corrected.

You guys are forgetting that it is an 8000 lb truck. I have a tuner, intake and a 4" turbo back exhaust. While drafting behind a semi trailer (very close) on a patch of interstate at 65mph, I was able to get a hand calculated 20.5 mpg. Now you are going to try and tell me that he is getting another 12 mpg better than that???
Also the fact that it's a 7.3l, not the more efficient 6.0l.
Not even with a rocket strapped to the back of it.

I believe it, lots of torque and probably more than normal boost, tuned.

Using the same logic I had a Geo Metro that only got 35mpg, there are people reporting twice as much as that here, well over 12 mpg better, so because my particular Geo Metro did not get it, then it is not possible they are getting what they claim either. Despite all the mods that they made. I have a 1.6l engine that gets better efficiency than the 1.0L engine that I had, yet again not possible because of the larger displacement? Is it also possible that his mods where installed in a more perfect manor and your mods where installed and created an error of some type. For instance I have taken a car to two different mechanics and one screws it up then take to another he fixes the mistakes of the first mechanic and the original mechanical problems as well. Yet the first mechanic has certifications to show he is a high level mechanic, but is incompetent in reality. The second mechanic has no paperwork stating his abilities, but obviously has more talent than the first.

Also might want to take into account what type of terrain and roads we are talking about. I could get much better fuel economy on certain highways that where flat going to the beach vs. say going to the mountains.

Just to set things straight, I've done over 50 on the overhead before, but this last tank has been the first time I've done over 40 mpg hand-calculated. Also, the Excusion comes in at 7,700 lbs curb weight, which is ~1,400 lbs heavier than my truck. That being said, we're talking about highway fuel economy, so weight isn't as big of a deal.

With regards to whether it's possible to do what the OP has claimed, I definitely say it's possible (based on my own experiences). That being said, I need to add a few things.
1) There's a huge difference in getting 32 mpg on one trip and consistantly getting 32 mpg. Note that the OP didn't claim he was getting 32 consistantly.
2) Related to the one trip thing, it's important to keep fill variations in mind. If we were looking at a long term fuel log that accounted for evey mile driven that would be one thing, however, on a large vehicle like this you can easily get 2-3 gallons of fill variation if you're not careful. That can easily add +/- 10% to/from the mpg numbers. So maybe 32 mpg is actually 29 mpg.
3) This was a one-way trip, so factors such as wind speed, etc. may have biased the results.
4) Has the OP verified the odometer. If he's changed tire size that can affect the numbers as well (both hand-calculated and from the overhead).
5) The OP says that he's "verified" the overhead display. It's sounds as though this was based on a one-time check. In my experience those things have a lot a variation built into them. I'd have to see some consistant comparisons over many tanks to trust the numbers (in terms of the absolute values).
6) Some one suggested that they'd like to see a video of a Scangauge. A SG is calibratable, so that wouldn't prove anything.

So, in summary, I think the OP's claims are believeable, but I'd like to see some more evidence. Assuming he is telling the truth, I'd like to offer him congrats!

Sorry for ignoring my post for so long, but I've been busy with other things. Yes, I can understand why there are some naysayers out there and I've since learned that not all Excursions are seeing the same results, even after they've performed similar modifications. I can honestly say this in no BS...

To help address some of the feedback. This was a one-way trip from Florida to Texas along I-10. The Ex runs on Michelin LTX in 265/75-16. In my opinion, one of the biggest advantages we had on the trip the stock springs were pretty well trashed. So, the whole vehicle was sitting nice and low.

Shortly after getting back from that trip, I rebuilt the suspension (raising the truck ~2" over factory stock) and have never seen anything over 28mpg since. Because this vehicle is seldom used for anything outside of city driving, it's very hard to come up with decent highway numbers other than it does get a solid 18+mpg in town when my wife drives it. Or, around 16mpg when I drive it, which goes a long way in saying that driving habits can make a significant difference.

On the trip we took to NM from SE Texas last year, we saw a round trip average of 25mpg with a fair portion of the hwy driving at 70-80MPH and a rusted out front hub.

By the way, I've never trusted the overhead and didn't believe what it was displaying when I took the original picture; I validated it's output over a period of several months of constant record keeping and didn't post the pictures until I felt the accuracy was plausible. When taking trips where I want to track the economy, I always hand verify. My current daily driver is a "tweaked" F450 that gets a sold 12+change wherever it goes and it's overhead display is only worth using for checking the outside temp and compass! :)

I know I'm bringing this thread back from the dead...however...college roommates dad had a 2005 ram diesel with the full banks treatment and he avereged 25-27 MPG. to me 30+ in an excursion is entirely plausable.

You also get about a +2mpg advantage being down close to sea level.

Ancient news here but I live here and commute I10 daily.
If economy is from Tx to Fla I can believe it because west winds fight me home just about every day and were not always talking about 15 - 20 either.
It can make my car drive like.. well taking up the whole lane.
The kicker is adding a sea breeze to that also.
Without the winds I doubt it alot but wont deny what I dont understand fully.

what about a 2005?
 

Hello.

Impressed to say the least.

I am wanting to get an 05 diesel (or 06 production 05 if I can find one).

What would the suggestions be to replicate this scenario for an 05?

I might have overlooked it but is this hand calculated mpg? My tuned 2wd cummins shows 25 plus at 70 on the overhead but only gets 22.3 when I do the math.

The 6.0 has a radically different engine and drivetrain compared to the 7.3s. So the tips and tricks are quite a bit different. There is a lot that can be done by simply deleting the EGR system and adding a good quality tuner. Anything to help air in and exhaust (all the things that typically make more power) can also can help to improve economy when combined with conservative driving habits. The best advise I can offer is to research which mods may give you the best bang for the buck and then go fourth and experiment. Economy was not my primary focus when this project started. So, luck had a lot to do with the end result.

Yes. See my later response on the previous page.

A fuel log would be helpful.

Both engines are heui design, oil pump is in a different location. There are some difference but a lot is just the emissions crap

Ah yes, I was thinking more along the lines of the 6.4L...

I don't miss the emissions gear, that's for sure. We deleted the Glow Plug Control Module after it burned up the second UVC harness. The EX is now mostly Super Duty under the hood after installing an F250 harness and ECM. I have some ideas of why, but still think it was a bad idea for Ford to run the GPs all the time without beefing up the gauge wire they used...

When did they start running the gp's all the time? The amperage draw on them is pretty massive to be doing that

I don't think it's documented anywhere, but it appears to function this way on Excursions equipped with the GPCM. None of the Super Duty models that use a relay in place of the GPCM do this. In my case, since my ECM was acting up, it made sense to switch to an F250 ECM and harness with the relays. I forget what continued to throw an SES code after the mod, but it was easily suppressed it in a custom tune.

What year 7.3s ran glow plugs all the time?
Glow plugs typically draw 8 to 12 amps each on a 12v system.

I wasn't the one who made the original observation, but it is my understanding this anomaly only shows up on 7.3s Excursions equipped with a Glow Plug Control Module. :thumbup:

I agree. However, 90% of my driving these days is back and fourth to work or the gym; about 2-5 miles. When I do get it out for extended driving I consistently see mid 20s. Unfortunately, I lost a lot after leveling it out with a 2" lift and 32.8" tires.

:cheers

I'm coming into this "conversation" rather late since I've never owned a diesel but I'm currently considering buying an Excursion. I'm indifferent to the 6.0 versus 7.3, so what do any of you recommend? Which is more prone to issues, easier / harder to fix commonly known issues? What are your recommendations for upgrades to improve mileage and what are the associated costs per configuration? I'm looking for a good long distance vehicle to haul a family of five and eventually a camper.

I've owned multiple examples of each, and I'd say the 7.3PS is a better all around motor. I currently own a 6.0, but only because it was so cheap.

7.3 doesn't make as much power, but it has vastly better reliability, lower maintenance costs, cheaper parts, and just goes forever. On a 6.0, any sort of mechanical work is going to cost you an arm and a leg, and the truck is going to be off the road for a while (cab coming off and all). Stay away from any sort of tuning software on the 6.0 without ARP/similar headbolts or you can be in a world of hurt shortly.

6.0 is a good, strong little motor but is a maintenance queen compared to the 7.3. Just changing to oil every 5,000 vs 7500 miles (7.3L), flushing the radiator frequently (sand from casting does nasty things to these engines), etc, etc really add up to higher costs over the long haul. Add in emission components that are VERY prone to failure (delete as soon as possible) and you are looking at fairly identical vehicles in which one is MUCH more expensive to own and operate over the long haul.

A one ton van is a far better tow vehicle and people mover than an Excursion. The Ex is, bar none, the worst tow vehicle of the last twenty five years. By any definition in handling, braking or reliability. And that's before the trailer is hitched.

My father's work truck was a 7.3L which he neglected badly after 100k. Very few (if any) oil changes but it still ticked like a clock when he sold it at 190k.

I bought into the high MPG diesel truck hype. Heard plenty of stories about getting over 20 MPG with a couple of mods and massive 4x4 trucks. I got a 2005 Duramax with Allison, tried some of the tricks for MPG and didn't go crazy with the power. It did have all the power I would every want or use but it never came close to getting good economy. I came to realize the owners were talking about very short specific MPG claims usually from the overhead. Then you take into account that diesel is $2.80/gal and gas is $2.10 here even if you could average 20 mpg on the highway a gas truck only needed to get 15 mpg for the same cost per mile. I looked at diesel Excursions but think realistically you wouldn't break 20 MPG very often even with $4000 in add ons. My gas SUV gets 18 MPG (that's hand calculated 70 mph, 300 miles, over two mountain passes in 30 degree temps on winter fuel) with no add ons and with the price difference in fuel that is like the diesel getting 28. It can't tow as much and is not as big but I don't need that much space or towing ability. 7 passengers and 8500# towing is plenty for me. Plus the ride on my Aspen is much better then any Excursion I have ever been in. The 2008 Aspen was $11,300 with 140K on it, better price then the few diesel Excursions we could find as well. They are the king if you need the room or ability to tow a massive trailer, I also just don't believe 32 MPG real world long distance unless it was 10 feet off the back of a semi-truck at 65.