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!