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Ford SD 7.3 Diesel Mileage.

23K views 68 replies 12 participants last post by  DoyleSumrall 
#1 ·
Anyone know what I can expect gas mileage wise on a Ford F-250 Super Duty with a 7.3 diesel engine? What if it's a standard transmission, any difference?

And would anyone know what the expected gas mileage would be on a Ford F-250 Super Duty with a 5.4 gasoline engine?

Thanks.
 
#2 ·
My dad had a 2000 with the 7.3L Powerstroke, extended cab/6' box, 4x4, auto. I'll ask him when I see him today, but I know the mileage was slightly less than a Prius. :laughing:

It's obviously going to vary a bit depending on cab/box configuration, 4x2/4x4, axle ratio, tranny, and of course the right foot.
 
#5 ·
I think the guy selling that white SuperDuty (linked craigslist ad) is full of crap. You don't regularly see those PowerStroke diesels running over a million miles. :no:

Anyway... A LOT of factors go into average mileage, but a 3/4 ton SuperDuty Diesel is probably going to run you upper-teens on the highway. A little less if it's a 4x4. The same truck, with the gas engine, is likely to run 13-14 on the highway. Again, a bit less if it's a 4x4.
 
#6 ·
A LOT of factors go into average mileage, but a 3/4 ton SuperDuty Diesel is probably going to run you upper-teens on the highway. A little less if it's a 4x4. The same truck, with the gas engine, is likely to run 13-14 on the highway. Again, a bit less if it's a 4x4.

Don't say that, I'm picking this one up this week. 2006 F-250 Super Duty, 5.4 gasoline V8 Triton. I'm hoping it'll get into the upper teens to low 20's highway, 15-ish in the city. I'll be adding a programmer or chip of some sort as soon as I can but for now it's all stock.













Under the truck.


 
#7 ·
Well, it looks like I'm a little late, but I'll still share what I found out for the archives....

Like me and my vehicles, my dad had a record of every tank of fuel he put in that rig. I just do it with a pen and notepad, but I checked out his Excel spreadsheet. His mileage varied quite a bit, anywhere from 10-20 MPG, mostly city, with 'winter fuel' representing the low end. It's hard to believe diesel fuel was in the $1.50 range back in 2000 when he bought the truck new. He kept it until about 3 years ago, and still regrets giving it up.

There was a slight increase in MPG after the Hypertech chip, and he said there was a noticeable increase in power, but couldn't recall the exact HP/torque increase.

To expand on the specs from my previous post, he had the 3.73 axle ratio. I'm not sure what, if any, other gears were available.

That's about all I got.
 
#8 ·
3.73 is stock differential even today, from what I've been led to believe talking with owners of 7.3's.

Not too late just yet, Jay. I have a few days to a week to pull the trigger. I'll admit it, I'm still confused as to whether it's the newer model 5.4 that attracts me most with the least amount of miles or for the same amount of money the older and near or over 200k miles on the motor diesels that can go for over 500k miles which most likely would save on gas but can cost over three times to maintain...?

I need to sleep on it, see how I feel tomorrow about it. Thanks Jay.
 
#11 ·
It's coming down to the nitty gritty. I'm checking this diesel out today to see if it changes my mind. It's a '99 with 174k miles. New clutch. Seller says it's in excellent condition. No leaks or anything.

Thoughts?

http://houston.craigslist.org/cto/3012330197.html
For what it's worth, I've got a good buddy who has a truck very similar to that one, except his is a 350 and (I think) is one year newer. He absolutely loves it! The only thing he doesn't like is that it's a 2WD instead of a 4x4.
 
#10 ·
You'll be very happy with that truck. I had a 96 F-250 Crew Cab 4x4 with the 7.3L Auto and 33" tires, and I once got 20.5mpg on a long trip. Of course, that was at 60mph with 4.10 gears, once I got to 70mph, it went down to 17 or so. If that truck is factory stock, it'll have 3.73 gears, since after 99 that's the only gears you could get with a 7.3L.

One thing I see with that Craigslist ad is that the transmission is actually a 6 speed, 5 regular ones and a compound low. That compound low is nice, you can sidestep the clutch with your foot off the throttle, and you won't kill it.

I'm glad you aren't getting that 5.4. These trucks weigh a metric s***load, and it just isn't powerful enough. The V10 was only an $800 option, and the mileage is almost exactly the same since the V8 had to work so much harder.

And if he says there are no leaks, he's probably lying. The rear main seals leaked from the factory. Its not a huge deal, because there's 15 quarts of oil, but just know that.

And when I worked for a Ford dealer, I had a customer with a 95 E-350 Club Wagon with a 7.3L, and 960K on the original engine. That was years ago, so its probably well over a million by now.
 
#13 ·
You'll be very happy with that truck. I had a 96 F-250 Crew Cab 4x4 with the 7.3L Auto and 33" tires, and I once got 20.5mpg on a long trip. Of course, that was at 60mph with 4.10 gears, once I got to 70mph, it went down to 17 or so. If that truck is factory stock, it'll have 3.73 gears, since after 99 that's the only gears you could get with a 7.3L.

One thing I see with that Craigslist ad is that the transmission is actually a 6 speed, 5 regular ones and a compound low. That compound low is nice, you can sidestep the clutch with your foot off the throttle, and you won't kill it.

I'm glad you aren't getting that 5.4. These trucks weigh a metric s***load, and it just isn't powerful enough. The V10 was only an $800 option, and the mileage is almost exactly the same since the V8 had to work so much harder.

And if he says there are no leaks, he's probably lying. The rear main seals leaked from the factory. Its not a huge deal, because there's 15 quarts of oil, but just know that.

And when I worked for a Ford dealer, I had a customer with a 95 E-350 Club Wagon with a 7.3L, and 960K on the original engine. That was years ago, so its probably well over a million by now.

I've seen on craigslist many 7.3 diesels with over 200 and over 300k miles and selling for close to and even over 10 grand.

I will be driving this thing a whole heckuva lot so most likely I will buy the diesel. It's also got a new cluth, one less thing to worry about.

I'll drive it tomorrow and make a decision then.
 
#12 · (Edited)
That's the whole reason this guy is selling the truck, he needs a 4 x 4 for towing farm equipment around. He's actually already bought the 4 x 4 and now just has this one taking up space, I believe. I don't need to tow anything but I will be filling the bed but even then, not even to capacity. That and driving long distance often.

Yeah, everyone I'm talking to is saying to buy the diesel, that 174k miles on it, especially the 7.3, is relative to a 5.4 at 40-50k miles, just barely broken in.

Plus the 5.4 is auto tranny and who knows how it's been used. That tranny could go tomorrow or it could go 100k miles from now.

I'll be going tomorrow to check out the diesel in the pic. Thanks everyone.
 
#14 ·
The marine dealer attached to our Ford dealership has a small fleet of 99-00 7.3's used to pull boats across the country for delivery. Last one I changed oil on had 834,000 on it, still runs like a champ. On it's 3rd clutch now. They all have mileage similar to that. The drivers absolutely love them, don't want to get newer trucks. Unloaded he said they're averaging 21 mpg highway.
 
#16 ·
That's the same thing everyone else is saying, that truck is barely broken in. And then I came across this one today. 2001 7.3 140k miles for only $5400. This entire truck shopping process is makng me bipolar, I'm so confused.

This one is an automatic and has a gooseneck trailer hitch which has me worried about the transmission, if it was used hard or not. I'm testing the brown two tone tomorrow and then this one the day after. By this weekend one of the three will be mine. I'll probably have a stroke deciding which one to buy and consequently not be able to ever drive it, but it will be mine. :)

http://houston.craigslist.org/cto/3000955892.html

 
#18 ·
The 4R100 transmission wasn't the greatest in the world. All else being equal, I'd get the six speed. I know people with hugely built diesels that run them without much problems.

That said, the auto tranny won't necessarily go out tomorrow. There are zillions of them, and they aren't all on the side of the road broken down. There is a place in Arkansas called Brian's Truck Shop that will build a 4R100 with a lifetime unlimited horsepower warranty, they're so stout. And from what I hear, people don't have any trouble with them.

That 5.4 truck you posted will have the newer transmission, the 5 speed auto from the 6.0L diesel. Its better, but the engine still isn't powerful enough for the truck.
 
#19 · (Edited)
I can't thank you all enough for your insight, this truck hunting business is not as easy as I might have originally unanticipated. I have no idea what the transmission is on which truck Mort is referring to. I'm assuming the auto..? Don't really hear too much about tranny's on standards.

I went this morning and checked out the 1999. At first glance when he drove up in it my heart came out through my thoat. Big mutha, pure tank, all diesel. Within the first two seconds of me driving it, before I even made it out of the friggin' parking lot, I apparently made the unconcious decision that this is the truck for me. By the end of the drive I told the guy I had no reason to hunt any longer. Everything about that truck was tight and no leaks whatsoever. Only thing that took me for a spin was the interior. As clean as it was, it was definitely a 1999. Compared to that '06 5.4 it was ancient. Very clean, but Flinstones. :) I just got out of a '98, I was hoping for something in this millenia and since I've already had the experience of the '06 5.4 I was a bit aprehensive.

Cold a/c. regardles of the interior the truck drove like a champ, solid. New clutch just awesome. Pure adrenaline speaking I decided I liked it enough. Had the company paper work written up (my a/c company is buying the truck and I'll in turn be purchasing it from them on payments) and I signed it, company was going to cut a check to the owner of the truck and overnight it to me and I was all set to pick it up this weekend BUT as I drove off I thought maybe I should check out that 2001 automatic first. That standard, as enthused as I was at first about driving it, takes some effort. Not much but enough to drain energy, especially after a long day of working in attics, I'd assume.

Here's some pics that I took of it. Tell me what you all think. Underneath pic included, no leaks whatsoever.











 
#20 ·
Sorry, the 4R100 is the 4 speed automatic that came in the 7.3L diesels from 1999-2003, and the gas engines from 1999-2004. They're alright, but aren't famed for their durability. With the new-for-2003 6.0L diesel came a new 5-speed-automatic transmission that was much better, and the gas engines got it for model year 2005.

You're right about the interiors on those 99s, they are pretty crappy. For 2001 they were upgraded a bit, and redesigned for 2005. If you're into that sort of thing, everything bolts up. You can go junkyard hunting and have a new-style interior for not much money.
 
#23 ·
Sorry, the 4R100 is the 4 speed automatic that came in the 7.3L diesels from 1999-2003, and the gas engines from 1999-2004. They're alright, but aren't famed for their durability. With the new-for-2003 6.0L diesel came a new 5-speed-automatic transmission that was much better, and the gas engines got it for model year 2005.

You're right about the interiors on those 99s, they are pretty crappy. For 2001 they were upgraded a bit, and redesigned for 2005. If you're into that sort of thing, everything bolts up. You can go junkyard hunting and have a new-style interior for not much money.

Before a friend of mine left to start his own electrical contracting firm, his company gave him a 99 F250 Powerstroke automatic to use for them. Back then it had over 200k miles and nothing ever done to it. Right now it's over 400k miles on the original motor and tranny and still being used by that company.

Just after he started his own company a few years ago he bought a used 2006 Dodge 2500 Lariat four door full bed Cummins Turbo Diesel, standard. I think it had about 40k miles. Two months later he had to have the transmission rebuilt. Yup, the tranny, not the clutch.

You just never know, I guess. The tranny on this 2001 I just posted is awesome.
 
#21 ·
I am so, so glad I didn't pull the trigger on that 1999. After a lot of stressful timing issues with this seller of this 2001 over the past few days we finally got it together tonight and I drove it. Not only did I drive it but I drove the Holy Bujeezuz out of it. Looks good, runs like a brand new truck. Suspension so much smoother than the other one it's unbelievable. Newer mirrors and running boards added to the truck and it comes with the tool box, a big old RK with the keys to lock it.

This thing simply blew that 1999 out of the water. And it's $600 less, due to the fact that up close you can see the scratches and there are a lot, I won't deny that, but you have to be up close to notice. Interior is the newer style, so much more comfortable. And check the mileage, 137,xxx.

This is the one. I knew it from the moment I hit the gas. :thumbsup:














 
#26 ·
My ignorance is costing me. I didn't realize the seller swapped out the diesel truck batteries for regular car batteries, about half the size and less cranking amps. They are both dead.

I figured on putting new ones in regarldess, just not so soon. Tomorrow.

Hmmff. :thumbup:
 
#28 ·
Why the hell would he do that? I wonder if he possibly swapped them out at the last second before the sale?

I think that's exactly what he did, but I didn't notice it the first time I went and checked it out either, nor when I actually bought the truck. The batteries have covers on them.

He's also get a newer F350 he's trying to sell. Maybe those batteries went dead and he needed the good ones.?

It's all good, I was planning on buying brand new batteries anyway, already had the money set aside for them. Tomorrow.

Now if I find out the transmission has been replaced with that of a Ford Focus', I'll be pissed. :)

Just to see what would happen, I took the battery off of my mini van and installed it on the truck. It cranked right over.
 
#32 ·
The finale! Well, tires in a week or two and then the grand finale!!

The batteries which were in the truck. 34-DLG.



Click this bar to view the small image.

The single battery I used from my mini van to start the truck, see if it would start with only one, which it did. Probably drained about half of it's remaining life in doing so but the van cranked right up once it was put back in so no worries.
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New correct batteries. 65-DLG.
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I removed the battery covers, couldn't get a socket on the terminal bolt with it on. Installed and now, peace of mind!
Click this bar to view the small image.


 
#33 ·
I just picked up these two Goodyear Wrangler Authority 265/75r16 AT E rated tires BRAND NEW for $200 for both, Craigslist. Had them mounted, balanced and installed for $20. Two down, two to go!

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I got them at a real steal! Those are $200+ tires each.
 
#35 ·
Those Wrangler Authority tires are made specifically for Wal-Mart by Goodyear, not sold anywhere else. They are a counter to the Goodyear Wrangler Duratracs.

I think I'll be hunting for (very good condition such as 90% tread left) used ones first. Being my first big truck I'd like to not spend a ton of money to figure out what I like best, at's or highway tires.


I outfitted my F-150 and my Ford Windstar for $460 with replacement certificates (which have come in handy I might add, two new free tires due to nails and going into a ditch which resulted in a ripped inner sidewall) walk out from Discount Tire. The truck received Khumo's and the Windstar got Arizonian's, made by Goodyear. Those were mid range quality tires, 60k mile warranty.

Not so for tires for this truck, twice as much to start. :eek:
 
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