The way the "Diesel Wars" is carrying on between the auto manufactures, this does several things to the consumer. 1- It encourages innovation to be competitive in the market place (Pro Consumer) 2- It substantially drives up the price (Con Consumer).

This same trend is happening in the snowmobile world as we speak, and has been for the last 10+ years. New chassis are coming to the marketplace every 2-3 years. In 14 years the cost of a new sled considered "premium" as nearly DOUBLED. While its great to buy a new sled off the dealer floor, only to have the manufacture price drop by $2000 within 2-3 months because lack of sales really hurts the consumer! I've found if you don't have to have the absolute latest and greatest on the current market, a 2 year old sled is what to buy. You have nearly the latest innovations but let some other fool take depreciation hit. I feel trucks are the same way.

Finding a used one that someone has taken perfect care of, gives me the same excited feeling as buying brand new.

 

i would love to update to a 6.7 powered truck.
but i can't afford one.

 

Perhaps one of the most consistent comments throughout this thread has to do with price, but these trucks are cash cows for Ford as they are for the other manufacturers. New pick-up trucks are big sellers and yes, you still have to pay big to play. But then, how is that different that for so many other things today?

 

Thank you for the warm welcome, Tim.
It is a refreshing change after the last page or so...
I started trying to write this reply about 11:30 this morning. But, this has been a family day, and it's a little later.

Also, thank you for the honest questions. I respond much better to actual dialogue than I do to passive aggression, eye-rolls, or outright personal attack.


Not at all. Questions are fine, unless a poorly veiled passive aggressive attack... well I've already covered that.

The truck is a standard 4R100 / 3.73. I could see that the tranny had been rebuilt at least once (probably more) when I bought it. I fully expected to do a rebuild or replace shortly after purchase. (So far I haven't had to)
At one time, I looked at trying to source a 3.08/3.09 ring and pinion for when I did my 250K mile overhaul. I just couldn't find one in the 10.5 / 10.25 Sterling flavor.

Anyway, the best mileage I got was in mid 2010 when I was on 1 month leave from Iraq. I took my family on a 28 day vacation that spanned from Tenn to Texas to Florida, and back to Tenn. Taking in to account that we were on a cruise ship for a week, I put just over 3000 miles on the X in 21 days. That still doesn't sound like much until you realize that once we got to the hotel or resort, the X usually didn't move for 4 or 5 days...
My best mileage that trip was 28.8 or 28.9MPG on one tank. That was a non-stop drive of just over 1000 miles, and I filled up just under 1/4 tank (really only because I wanted to check mileage before driving around the town in which we just arrived).
In the interest of full disclosure, it bears noting that this was before Harpoon Mod was done. A "full" tank was very dependent on the slope of the filling station, and the pumper's tolerance level. That said, I've always done my best to really pack it in at filling time.

As far as calculating fuel economy: Miles on the trip odometer / Gallons pumped.
The wish-o-meter is cute and all, but it isn't reliable in the least.
Mine actually reads fairly close on average (I'm guessing the PO had it corrected in the program), but it may be a few MPG high one tank, then a few MPG low the very next.


And now, the rest of the story:
My next best mileages were in 2012, but 26MPG was about it.
One obvious factor was that I was not running out an entire tank in a single drive. I also think a decline in fuel quality was also a contributing factor.

By the end of 2012, my mileage had dropped to 19. The next tank was 17. I hadn't really been driving the truck much during this period, only filling it three times the last 6 months of 2012. But, under 20 was just unacceptable for me.

I knew the fuel bowl drain had been leaking, so I replaced the o-rings. After washing out the lifter valley with some Dawn detergent, that stopped the diesel smell under the hood, but did absolutely nothing to improve mileage.

It wasn't until the engine started skipping at stop lights that I found out the dealership had stolen my CPM something like 9 months before. The truck was in for the CC Brake Switch recall. They said NOTHING to me about the CPS... They just took it.

After I replaced the grey turd with a Standard Motor Products PC139, my mileage jumped back up to the 24-25MPG range...

For the last year or so, I have been working offshore. So, my one-way drive is right at 550 miles. A few trips I babied it trying to get round trip on one tank. If I filled up right when I left, drove the speed limit, and held my breath, I could just make it. None of those things are in my nature.
I'm just more of a gasbuddy and radar-detector kind of guy...

For instance, my crew got off the rig Christmas Day this past December. I pulled out of the Heliport parking lot right at 11AM. I pulled into my driveway at 5 till 5. It goes without saying that time would have been better without the 30MPH speed zones and accompanying stoplights.

And now you have the cliff-notes of my fuel economy history...


I am familiar with Dave. I'm all for doing things to get better fuel economy. That's one of the reasons I absolutely do not buy into the Big Tire / Big Lift culture. (Safety is another "Big" reason)
But I could never see myself going to his extremes. I've also never liked tonneaus. Wind tunnel tests have proven conclusively (at least for me) that while they offer a slight improvement in fuel economy, it is marginal at best. IIRC, it's something like .25 or .3 MPG for the average full size P/U.

Thanks for the links though. I do like to read stuff like that. Maybe in a few days I'll get a chance.

Anyway... speaking of Dave and his tonneau blowing up:
I recently (this past month) had a situation where a tonneau cover was creating an issue towing. The guy had a F-150 Super Crew pulling a 24 or 25 foot "V" nose toy hauler. Any time he would get over 60MPH, the tail would start to wag the dog quite badly. I've pulled the same trailer several times with the X, and not even known it was back there. I pulled it with another P/U last year, no issue. For giggles, I asked him how hard it was to remove to tonneau.
When he took off the tonneau - 75MPH, no problem...
I'm sure a flat-faced trailer would not have had the same issue. But, I'm still filing it in my "Why I hate tonneaus" folder.

 

LurkerX: Well, when you think about it, I guess with his tonneau cover, Dave is really trying to build a swept back version of your Excursion on his non-lifted 2wd 7.3. Assuming you once took an oath "Not to lie, cheat or steal or to tolerate those who do", your bona fides are good with at least me.

There are those who come here looking for big hp with big injectors -- nothing wrong with that. And then there are those who just want their rig to be the best, most fuel efficient, most reliable rig it can be. Especially since you've been through an overhaul of your rig, you have a lot to contribute here and, personally, I hope you do as often as you can.

 

Check out gearvendors.com

Quote from the site (is this allowed?):

Though not interested in gear splitting (I just want a 2X OD), I checked into it.
As I understand it, it is a fully automatic module.
2WD operation only, though. Not that I see that as a problem. You can use 4WD, it just disables the system.

 

Interesting choice of words...


And I'm at the opposite end of the spectrum. I don't mind power. Heck, I like power.
But, I feel my tranny slip and strain everytime I get even a little heavy on the throttle going through the gears.

More my speed. When I crank this truck, it's often for a 1000+ mile trip. Any way you slice it, laying down 500 miles from home is much more expensive than crapping out 2 miles from your driveway.



Ehhhh...
I've done a lot of stuff to the motor, but I've never been in it.
When I do, I intend to oversize the bore, deck the block (and possibly the heads), all in an attempt to raise the compression ratio as high as possible.
I know this is counter-productive to Big HP - But, Big HP is not my goal.
Past experience has shown me that high CR (23:1 or higher) diesel engines are MUCH more fuel efficient. Granted, I'll have to reduce max boost a little more - but, mileage should (theoretically) improve, and cold starts will be faster (although I no longer have issues with cold starts).

Maybe. But I don't think I know anything that hasn't been covered before. The 7.3DI has been my introduction to electronically controlled diesels. And in most ways I really don't like it.
I'm good with an injector pump. I've rebuilt plenty that "can't be rebuilt".
But it is cool that you can make such a drastic change in how the beast runs, and never get your hands dirty.
And to the end of what I may have to contribute, everything I know about the 7.3 has come from years of browsing forums like this one.

 

If you only do 3-5k a year stick with a non-payment 7.3

there is no comparison in towing/pulling with a 7.3 vs a 6.7 but a huge one with the payment/insurance cost of a 6.7


how much more heat do you think you will add with a setup like this??

 

You're actually severely limited in how much the deck and heads can be shaved. So, actual, realized, CR increase will not be that much. However, it would absolutely be the wrong direction to go if one were looking for a foundation to obtain "Big Power".

However, the question on heat is a good one.
Strictly speaking, the 7.3 has far more radiator than is necessary. I've seen AC cores, Intercoolers, and radiators so stopped up that air con't possibly move through them... and the only thing that is overheating is the transmission.

 

LurkerX: AF Academy Code. I was just taking a stab in the dark: Iraq + helipad may equal AF Academy or OTS. I never served myself, but have known others who have.

Again, I like the "new to me" way you are looking at the 7.3. I personally don't have the knoweldge or experience to evalutate your ideas, but others here do, and we can all learn from that interaction. So, keep it coming. The real engine gurus here (and there are quite a few) will address your ideas (e.g., comment, question, attack, or agree), but not attack you personally. You can stand the heat.

I was told, in 2002, when I bought my van that the reason for the 7.3 PSD's (potential) longetivity was its lack of efficiency. That the 7.3 was about 40% efficient. Which meant that it did not overheat or stress out engine components. Comparing a new platform to the 7.3 PSD it would seem that using today's new knowledge and new technology to tweek up the efficieincy of the 7.3 platform could be the best of both worlds. I mean how friggin' hard can it be to adapt a common rail injection system to the 7.3L? It's just a pump with injectors which are told to fire by the PCM right? There's a guy over at the sportsmobileforum who is putting a 6.7 into a E350 and he is interfacing two different PCM's to do so. http://sportsmobileforum.com/viewtop...mins&start=195 This is rocket science, but there are rocket scientist diesel enthusiasts among us.

I encourage you to start a thread on Increasing 7.3 PSD Engine Efficiency.

I remember asking Tugly a stupid question when he put bigger injector nozzles in his engine. My question was something like this: "Wouldn't you want smaller nozzles for better atomization to burn less fuel for the same amount of power output?" It was a stupid question at the time given his goals. And maybe it cannot be done for technical reasons which are beyond me. But I would like to keep the torque band in the low rpm range, use less fuel, sacrifice some longetivity if necessary by increasing cylinder heat but finding ways to remove the excess heat.

Just so we are clear, I don't know anything, but I will tell you this, there are those here who do. Off the top of my head, if you do start a thread and you start drawing input from Cleatus12r (longtime PCM tuner formerly for PHP), Pocket, and some down and dirty practical engine rebuilders customizers like SkiSkyJason and Christof13T. Don't **** them off, because they have a wealth of technical knowlege and real world of experience which could push this engine to do what you are considering if it is possible. And I would guess that you would have to fool with start of injection/start of ignition/timing to accomplish what you are thinking and the advice of people like Cleatus12r (who can be prickly at times because of having to deal with internet fools like me) will be golden. I hope you wil start a thread and share more of your ideas.

 

If you find the truck for you you'll know it. I had an emotional attachment to my old 7.3. When I found MY truck there was no question in what I needed to do. I am not brand loyal, all have their perks and down falls. When I traded my 7.3 in i got a few thousand more than it blue booked for because of what it is. The price I got off set the price of my new truck so the price wasn't bad.

 

Something else to toss out there. Go ask around in the 6.7 forum about the high mileage vehicles or doing mods that will jeapordize the warranty.

Seems most of the folks in the 6.7 section are of the opinion they wouldn't own the truck out of warranty. Buy the extended warranty they say. Sell it before the warranty is up they say.

Don't know if it's just a different mindset from the folks spending that kind of money on trucks or if there's really that much to be scared of.

 

I recognized the quote. I am prior service... AF.

However, Iraq was 2 decades after I left the service (civilian contractor).

And "heliport" was working offshore on an oil platform...
Although, for several years in the sand box, CH-47s and Blackhawks were my taxis.

I've actually seen a few posts about interwebs regarding running a high CR on the 7.3. I have never seen a response other than "you can't make HP doing that."


I may disagree somewhat with that last part...


Not bad summation...
The T-444E is a 7.3, with about 1/2 the power. As a general rule of thumb, they last about twice as long.
The 6.0 (and I'm talking about Ford's engine here, not the Navi VT365) makes about 50% more power than the 7.3 on roughly 20% less displacement.
There are those that say the 6.0 has reliability and maintenance issues... /sarcasm

Ha. This is conversation that go on for hours...
In the strictest, most basic definition of the term, the 7.3DI (or 6.0) are common rail. Anything that doesn't have an individual tube running from the injection pump to each injector is on a common rail.
So the 7.3 has 2 rails, with 4 injectors each.

The modern use of the term however, implies a system with fuel pressure in the thousands of PSI, rather than low fuel pressure as in the 7.3.

To that end, adapting a modern common rail system to the 7.3 would, at the very least, require a complete head redesign.


I would be hopelessly under-qualified. I've never done anything but basic mods that seem to have yielded out-of-this world results.
95% of my experience with diesels is on mechanical injection systems.
Added to which, I really don't tinker with my truck that much. I have plans, but they will all depend on a major rebuild, having to pull the turbo... major service events.

Heat is not a bad thing. It is what makes diesel work.
Rudolf Diesel called his engine a "Heat Engine".

The problem we have with our engines (all of them) is the range in which they will operate. To control the heat produced, we use a thermostat to control cooling, and other means to mitigate overheating.
If we could actually keep cylinder, head and block temperatures at say 500°F, you could possibly double fuel efficiency.
Even if we had materials and fluids to do that, increasing power maybe just 10%, could get your temps into a range that starts melting things.

The other side of your statement, low RPM, also could make a huge difference. Slowing the engine speed allows several things to occur.
1) More time for expanding gasses to "push" again the piston crown.
This increases the amount of energy transferred from the burning fuel into mechanical motion.
2) A reduction in the energy required to move air into the cylinder for combustion, and in the energy required to evacuate the exhaust afterwards.
In every mathematical model I've seen for an internal combustion engine, the energy used to move air is much greater than energy used to overcome friction in the engine's mechanical parts.

LoL, Might be too late...
Pocket has already started a pissing contest with me in another thread.
And given his approach to me... I'm done with him.
I don't know how he regards me (I suspect absolutely nothing positive - and I'm OK with that), but I am to the point that if my truck were on fire, and he was the only person within 100 miles with a hose or a bucket of water, Baby would just have to burn.
It has also been pointed out to me that he is highly respected here.
Given that I have no future plans to bow to his greatness, I doubt any of his buddies will be eager to sign up on team Lurker.

As I mentioned earlier, I'm not in a hurry to do anything soon.
I've got my truck now to where I turn the key, she cranks.
I point her, and she goes.
Work is uncertain now, but when I need to go, I need to have faith that my vehicle can drive 550 miles... maybe 850 miles - sit for 3 weeks, maybe 5 weeks - then crank without issue and take me home.
And, even at 300K miles, I trust my truck more than I trust my wife's 2014 Toyota with less than 20K miles... And I like Toyota.

The extend of my future upgrades are limited to an AIS, and bypass oil filtration.

 

Based on my personal observations with their reliability (friends have them) I would punt before warranty on all the new diesels.

Which is why I went the route I did.

For some, the payment on a new(er) rig is actually less than the average expense the 7.3 repairs etc were costing......every situation is different.

 

Wonder whether the guys in the 6.7 forum would agree with these statements regarding the reliability of their trucks and what they might say about ours.

Also wonder, if in fact money were not an issue, how many folks would jump to 6.7?