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Over at TDIclub.com where I go for our other vehicle, a guy is trying to claim that a 2002 F-250 can get over 30mpg on the highway...is this even possible?

A Ford F-250 Diesel with the gearing changed to 262-1 rear end can hit 30+ mpgs on the highway . I saw this in a 2002 model that a friend has . It will not fly off the line now 0-60 mph but it still can pull almost anything and achieve 25-32 mpgUS all day long .
The whole discussion is here "Gas tax holiday" bad idea? - Page 3 - TDIClub Forums

Maybe 30mpg in gear coasting downhill?
 

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Is a 2.62:1 gear ratio even available for these axles? I doubt that truck could pull anything.
 

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Wow. Nice to know, but waist of a 'truck'.:icon_rolleyes:

Heck, might as well swap out that old 351M in my dad's old Mercury Montego and put in a 6.9L IDI. It has a 3.00:1 axle. :lol::lol:
 

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BS

Over at TDIclub.com where I go for our other vehicle, a guy is trying to claim that a 2002 F-250 can get over 30mpg on the highway...is this even possible?



The whole discussion is here "Gas tax holiday" bad idea? - Page 3 - TDIClub Forums

Maybe 30mpg in gear coasting downhill?
I had a 98.5 Dodge/Cummins with Gear Vendors and it could do 20-21 highway at 65-70 and that is pretty darn good. 30 plus is a pile of poop!
 

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I would say it "MAY" be possible but it depends on lots of variables. If it's a reg. cab 2WD 5-speed or 6-speed manual cruising about 30-40 mph with a bed cover or topper with a tailwind then it's possible. But if it's a 4-door 4WD with A/T He better have a REALLY strong tail wind!:lol:
 

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It's completely possible.

First, notice that he's claiming 28 average mi/gal. Second, notice that there's no mention of his driving style, location or the weather. (Warmer air = lower air density = less aerodynamic drag. So does higher altitude)

In 1986, it was possible to buy an F-150 that tested out at 20/25 mi/gal. That was with a 5.9-liter gas engine and a 4-speed, neither of which were really designed or calibrated for fuel economy. (if fuel economy was your priority, they offered the Ranger and the Courier)

An F-250 is about the same size and has about the same drag as an F-150. With higher-pressure, lower-rolling-resistance tires, conservative driving and the low final-drive reduction ratio, it's not terribly surprising.


Have you ever noticed that an 18-wheel Class 8 tractor-trailer is ten times the weight and has five times the frontal area of an F-250, but consumes only 2.5 times as much fuel?


Start with a final drive ratio that results in the engine turning 1500 rev/min or less at the posted speed limit. Ditch the overdrive; that adds a pair or two of gear teeth in mesh and will cost you 4%. Ditch the notion of 300+ Hp and install something much more reasonable. (ever notice that 80,000 pound semis have about the same horsepower as a Superduty?) To restore the pulling power lost, add two more gear ratios below what's now called "first". Give it a reasonable amount of ground clearance and clean up the aerodynamics. Finally, keep it down to the posted speed limit. (Better yet, run the Federal Test Procedures for consistency)

30 mi/gal doesn't even sound difficult, if there's a desire to do it. Unfortunately, horsepower, not fuel economy, sells pickup trucks.
 

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I think it would be possible but it would take more than 2.62 gears. I mean I have seen guys with 4wd new cummins with only a programmer getting 22 mpg and the guy that rebuilt my tranny got mid 20's out of a std output cummins doing 65mph. The problem is all these guy that blast down the highway doing 80 then complain that they only get 16 mpg.
 

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Like drcampbell, I think 30 MPG is entirely possible.

3.08s were very powerful for me. 2.63s would be much better.

I think some aero mods are a necessity.

2.63s imply they are not using the 10.25 or 10.5 axles most Super Duties come with or they have source of custom-hobbed gears.
 

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I WOULD NEVER BELEAVE IT UNLES I GOT 30M.P.G. also!!! 4X4 35s, 20 Harley rims , early 1999, 4 inch pipe, Edge CS programmer, 150,000 miles on the clock, extended cab, Louvered tailgate, louvered headache rack, and I run the soy deasil with that new Archoil in the fuel and the oil. Its got a big trans cooler on it and the banks intake. Its got the small turbo from early 1999 and it dose not smoke a little bit. This is also going 65 on a round interstate 100 mile trip. I don't believe it myself? The suspension is all stock except for Billsteins. IT HAS ALWAYS HAD ROTILLA IN IT. All I know is I got the truck and it wouldn't get 20. I got the chip and only ran iy on towing. Still 14 city 16 highway going 50. I put the airbag, upped the tune to the extreme, started running Archoil, put the levered bull rack on it and started running the tire pressure at 75/80 psi. All the sudden I saw 30 ampg? Didn't believe it even though the edge had the tires programed in. Still couldn't believe it. Got my gps put on it, filled the tank till I could see it in the fill tube. Then went for a 103 mile run. Pulled back in the same station and couldn't get but a very little over 3 gallons in the tank and spilled some down the side of the truck. I still don't get it? Say I am full of brown ozy dodo . I would say that if I heard someone clamming this. Only other thing I did to the truck was change the rear oil and added some Lucas, which shouldn't help should cause drag. Still I got 30 mpg at 65 mph on a round trip. Smaller turbo, smaller injectors because of it being early 1999? I think you guys need to try that snake oil Archoil. Can't say 100 what mad the change or if it was a little of everything. I STILL DON'T BELEAVE IT AND I PROVED IT TO MYSELF. Someone tell me how I could of messed up the math? I just don't know. Seems everyone else's truck smokes but mine with the 7.3. Mine used to smoke before the changes not bad but could see it now and then. Now it never smokes even at start up in the cold, I do plug it in though. Please tell my why I am wrong. It just makes no sense to me. Back around town it still only gets 14 -16 on short under 5 mile trips.
 

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What was the ambient temperature when this occured. If you have a return, which I believe 2002 does, the engine can heat the fuel up expanding it in the tank. If you let fuel cool back to ambient temperature before you fill you may get another number. Especially since your only talking 3 gallons
 

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While I'm skeptical, my 7000 pound plus 97 F350 Crew Cab Dually got 20.7 at 55 mph. So I'm sure it's possible. Now, can we/do we drive in such a manner in every day life? Probably not.

That said, I drive a 2018 Freightliner Cascadia. Fuel economy in these class 8 trucks has improved by 35% in the last 5 years. These trucks would typically get 5-6 mpg, empty or loaded. With the software and improvements along with auto shift 12 speed transmission, this 455 hp, 1750 ft/lb beast gets between 8.5 and 10 mpg. And it's funny, many people don't want a diesel citing maintenance cost. This 900 cubic inch Detroit Diesel goes 75K (yes, thousand) miles between oil changes. The cost is around $460 for all filters (air also) and 11 gallons of Delo. So, diesel technology is still improving folks. And I'm about to roll over 300K miles this week. We typically roll about 5000 miles a week.
 

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If anyone wants to know about real MPG with a super duty all they have to do is go back and look at the work Dave Whitmer has done!!! Most all the other high MPG posts seem to be smoke and mirrors or just plan BS. Not really ready to put much faith in a one post wonder. Put a load like a 12,000 lb 5th wheel on a F250/350 and you will be down to 10-12 mpg. Soooo can it be done, yes. BUT!!!! It would be a very custom rig and not a 4x4 crew cab tow monster. Dave could you get the gearing using an overdrive unit?
DENNY
 

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If anyone wants to know about real MPG with a super duty all they have to do is go back and look at the work Dave Whitmer has done!!! Most all the other high MPG posts seem to be smoke and mirrors or just plan BS. Not really ready to put much faith in a one post wonder. Put a load like a 12,000 lb 5th wheel on a F250/350 and you will be down to 10-12 mpg. Soooo can it be done, yes. BUT!!!! It would be a very custom rig and not a 4x4 crew cab tow monster. Dave could you get the gearing using an overdrive unit?
DENNY
My old 97 would get 10-13 mpg towing RV's 9-13K at 62 mph. My 2011 will get 9-10 mpg at 75 towing my 17K Fusion Toy Hauler, and might I add, with no effort! I haven't checked it at slower speeds.
 

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When I get off my lazy butt I want to try a air dam. What I really need is a gearing change just not sure how to do it. Not a big deal for me because I do not drive that much anymore, just kind of fun stuff to try.
DENNY
 

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30 mpg with a 7.3?

I think somebody’s calculator needs new batteries.

?
 
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