Increasing Mileage on the 7.3L

[rowekmr]

Hello everyone it looks like I finally will be able to get my first diesel. I was looking at 99 and up Crew Cab's and a few Excursions with miles from 180K to 240K (my price range). It won't be my daily driver but it will be occassionally driven empty to work and mainly for towing duties for my boat and travel trailer which weigh 8K and 9K loaded. I am looking for a crew cab 4x4, SRW with stock tires/rims. Some say they get 13-16 mpg's on the highway and a few say they get 20 mpg. I was wondering how can I increase the mileage to get around the 20's on the expressway around 65 mph if it is possible and not too expensive. I am replacing a gas SUV (5.4 32v) that gets 16 mpg that does the towing (6-8 mpg towing) and want to at least justify the change by getting better economy with the better power if possible.

[RT]

Stock rims and tires will go a long way - especially E rated tires inflated to the upper levels. I run 70 psi in mine. Aside from maintenance issues (like brake caliper pins and good fluids all around) the biggest issue is driving style. If you get a ScanGauge II or similar that shows you instant MPG and drive to maximize this, it will really help. Keeping RPM below 2000 RPM is a big deal. Still, I've never gotten below 16 MPG on mine even towing a trailer.

[rowekmr]

Thanks
How heavy is your trailer? What can you get empty?

[badbart]

You should get 20+ mpg empty if you drive it right. Like RT said, 2000 rpm is the majic number. I've gotten as much as 20.7 with my F350 running 55 mph on flat ground and I have 4:10 gears. Usually 18-19 though. I get between 10-13 towing 8000-15500 lbs. I do have a 4" exhaust system and a programmer though. Best I got before was 16-17 mpg empty.

[TooCoolTwo]

On a good day unloaded highway @ 60-62 MPH or 1850 RPM, I can get 20.0 MPG. Mostly, I get 18-19 MPG highway at the same speed.

Towing at the same speed and RPM, I can get 13 MPG on a good day. Mostly 12-13 MPG. Mine is a 2WD model seen below.

What RT & others says is right. Mostly air up your tires, stock rims and drive it under 2000 RPMS. Keep as much weight out of the bed as possible, clean fluids and filters.

That is about all you can do. These are big heavy trucks engineered for hauling and towing heavy loads.

[Bamaman1]

My 7.3 crewcab 2wd F250 (107K) was getting 18 mpg running the interstate @ 75 mph and around 2100 rpm's.

The D-P 80 hp econo mode improved mileage to 20 mpg consistently on 4 lanes/interstates. It's quite impressive running, however.

If I was wanting just a little more mpg for a fair investment, I'd go with the 6637 air cleaner and change over to the Walker muffler for just over $100 total. A TruCool tranny cooler is also a great add on @ just over $100.

D-P's 80 hp econo program is just good for 6500 lbs. towing. You'd have to drop back to a 60 hp tow mode for what you're needing to pull. Gauges would also be required on any diesel pulling moderate to heavy loads.

[FarmallBobM]

Originally Posted by rowekmr

Some say they get 13-16 mpg's on the highway and a few say they get 20 mpg. I was wondering how can I increase the mileage to get around the 20's on the expressway around 65 mph if it is possible and not too expensive.

Stay away from any truck with a 4.11 rear end - the lower gearing torpedoes mileage!

Like others mention, run stock tires/rims, keep tires aired to the max, make sure the brake caliper pins are free, and drive so stays RPM below 2K ALWAYS, and you should see 20 - 22 mpg out on the highway.

Pulling a 4,000 lb trailer with my '99 I routinely get 20 mpg on the highway running "summer blend" diesel. (Winter blend fuel drops the mileage by 2 - 3 mpg). Running empty I can get 22 or a bit more depending on the terrain.

[David C]

These are good trucks in general, and mine has been very dependable to date. It is the favorite vacation travel vehicle even though other more seemingly ideal and now newer family vehicles have been available. Plenty of power going up Pike's Peak. Holds all the luggage, bikes, etc., and souvenirs purchased along way! Get one, preferably a 7.3L.

Manual transmission should yield one to two mpg advantage over the automatic.

Compare only mpg data from those who confirm that the number was calculated manually, not from the computer readout. The computer can be consistent high or low, or erratic compared to manual calculations. And if a programmer or chip is installed the computer can get extremely wild from reality.

I mostly run next to empty, but once or twice a year do pull my camper a tank or two. When I was commuting (before retirement), I consistently obtained 16.5 to 17.8 mpg traveling 75 to 150 miles daily, week after week for years. With the camper behind it seemed to run about 9 mpg. After retirement with more local driving in the mix, I am running 15 to 16 mpg empty. Several month-long cross country trips (around 7000 miles each) with luggage for two yields around 16.5 mpg, with random tanks indicating low 17s. Only one tank in 12 years have I obtained an exact 18.0. The Ford manual says to use at least 1000 miles in calculating mpg.

The overhead computer will indicate a tank average of from three to eight mpg higher than the hand calculated numbers I quoted above. I have all my data in a spreadsheet from the day the truck was purchased new.

I do have a chip that is seldom installed. When in use the actual hand calculated mpg drops about 0.5 to 1.0 mpg from above numbers running empty. However the computer displayed numbers run extremely high and wild, indicating up to 29 mpg at times. Running my Diablo chip increases the EGT too high when towing the camper or climbing mountains empty, and as I never know when I may be towing I have gradually discontinued mounting the chip.

Good luck in your selection. One last commentary.... I love diesels in general. However when I purchased diesel fuel was priced about the same as regular gas. Today with diesel priced about 50 to 70 cents higher than regular, I doubt if economy of operation is there. Fuel and oil costs are considerably higher such that I doubt I would come out even at best. My previous gas truck delivered about 18 mpg empty and 12 mpg towing. I bought in a different time and because my gas truck was nearing its service life expectancy.

[mtnsammy]

I find oil changes, wheel alignment, DieselKleen additive and no lead foot helps me alot. My dually 2WD was getting 17-19 regular and 13-15 towing. Real heavy towing, 15,000 5th wheel, I could drop down to 10MPG but unlike the gassers I did not slow on every hill. I bought the diesel for the power not the MPG's/ It is nicer getting higher MPG but climbing the hills at speed is much nicer.

[INFRNL]

If you want mileage, do not get a dually and a manual if prefered. Supposedly a dually will lose 1mpg or so over srw and automatics will lose the same from what everyone says.

I obviously did not do my homework when I got my truck. I have an automatic dually with 4:10's. Best I have gotten is 14 or so city and 17-18 hwy(empty).
If I had 3:55's or 3:73's and a manual, I would get better.

[dmd]

If you get a 2WD you will get a mile or so better MPG. If you get a 4x4 CC expect 17-19 MPG hiway at 65mph and 14-15 mixed. NOw if you drive 75mph you will see around 16mpg because you are over that 2000 rpm line. 2000RPM gets you about 65mph with 3.73's and stock tires

If you drive like a old lady you can squeeze out a little more.

You will see much better milage towing than a gasser, but expect 10-12 MPG towing your wind pushing TT at 65MPH. Dont expect 18mpg. With the boat should get 14-16
mpg depending on how well it sits behind the truck.