i recently aquired an 1996 ford f250 7.3 psd 5 speed long box extended cab 4x4. i just took an 500 mile trip in it and only got 16.5mpg empty i used to have a pre powerstroke 92 7.3L 2wd that got 23mpg empty so it seems a little low to me. this was stright highway miles crusecontrol set between 70-75 the previous owner is a good freind of mine was always bosting about getting 19-20mpg out of that truck. and i have used it on meany occasions in the past towing heavy loads and gotten 12-14 while towing 10,000+. it was below 0*f outside and i was running #2 with and howes anti gel. i was wondering if maby the cold was the reason for my fuel millage. also somtimes on down hills i would hear a hissing sound probably the BOV and seemed to loose power when making this sound. probably normal i dont know my previous 7.3 was a non turbo

 

Theirs a couple key items to look at first when compairing mpg, what are the rear end ratios? Was the 92 an auto? 2wd vs 4wd
On my 97 I can adverage around 20 on the highway empty, hook up the goose and it drops to 16 or so w/3.55's With 4.10's/auto in the crew cab I never saw 20mpg empty

 

Winter blend fuel is always lower mpgs. Also as already stated your ratios will make a difference. And there is always a difference between the weight of your foot and the previous owners.
If you only drive down hill with the wind at your back you will do better.

 

I get 14 -16 in the winter even with an open exhaust last summer i was getting 19 -22 mpg Truck hasn ' t seen much of a load exept plowing go figure I get better mileage in 4wd in the snow than on a dry day in 2wd. I was told it was my heavy foot LOL!

 

I have found with mine if i keep it under 70mph i can get 19to20 miles per, if i do 70 plus my milage drops to 16to17 miles per.

 

But all and all i average right at 18 miles per with daily driving.

 

The key is the RPMs.

Try to keep RPM's below 2000, 1700-1800 is best, unfortunately that means traveling at 60-65 mph.

Notice the difference in top speed from 1500 rpm-1700 rpm, it's a nice spread, but then the ratio thins out speed/rpm the higher you go, you end up spending 100 revolutions to get a 2-5mph increase in speed. So you need to ask yourself what is more important to you. Speed, or MPG.

Choose... but choose wisely.

 

well i think we can take a heavy foot out of the equasion cause it was stright highway miles with the cruse controll set. for about 200 miles of the 500 i had it set at 70mph for the other 300 i had it set at 75. although i agree that a few hundrid rpms would have a differance on fuel millage i dont immagin a 4mpg differance out of a couple hundrid rpms's also a few weeks ago i was getting better fuel millage i dident check the acual numbers but my gas gauge was dropping alot slower. it was quite a bit warmer and i was running #2 with no howes. yesterday i was running the howes. also do you think mu truck would benifit from adding an intercooler on an otherwise stock truck

 

in my truck i can get 19 mpg while driving 55-60 mph. thats 1500 rpm at 55 and 1650-1700 at 60 mph.

just by bumping up to 70-75 mph i drop to 15 mpg. 70 mph is 2000 on the nose and 75 is about 2100.

this is all unloaded running 4.10's on 315\75\16 tires

 

an intercooler on any non-cooled truck is a benefit. you wont see any performance gains on a stock truck but you will see a very significant drop in exhaust temps. also get rid of the stock downpipe and get a good intake to really boost power and economy

 

My truck gets 20 mpg at 1700 and 63ish mph. If I bump up to 70 mph, rpm shoots 2000-2100 rpm, and I drop to 15 mpg. It is a 5 mpg drop for 5-7 mph.

I agree if your mileage droped 4mpg with the same driving habits there is a problem, but highway driving with cruise control set does not eliminate "heavy foot syndrome" per se, as RPM still affects it. So I would still say, your culprit is the cruise being set to 70/75mph. Try it on whatever speed is at 1700rpm for your truck, and try it again.

It's your truck though, do what you want, just trying to help.

-Iasrap

 

i have found that cruise set at 1500 is the best mileage i have ever gotton but that limits me to 55 mph and thats a bit too slow

 

Hey Coonhunter,

What do you get at 1500rpm as opposed to 1700 RPM for your mpg?

I'd like to know for my patience/mpg trade off.

Thanks,
-Iasrap

 

consider yourself lucky, i get 12 mpg empty, no matter what i do

 

well i just took it for a run down the freeway and i get 2000 at 60mph im wondering if my speedo or my tach what are the door coads to check axel ratio's 75 is right around 2500 rpms