Do all stock 7.3's run like this?
 

So last weekend I drove from Amarillo,TX to Austin pulling a 30' enclosed gooseneck that weighs in at 7000lbs loaded both ways. The truck was an '02 f250 ext cab, 4x4, 3.73 gears and an auto. The first part of the trip it did good until I stopped in Abilene for fuel. 33 gallons burned in 275 miles, 8.4 mpg.:td: From there the rolling hills started. Up the hills I could run 60 max in 3rd gear and in OD I could have it mashed to the floor and it responded like an old 6.9 would, nothing. 80 miles later was Brownwood,Tx. Burned 17 gallons getting there which equals 4.88 mpg :jump:. At this point I'm glad I'm not the one paying for fuel. After 10hrs I made it to Austin, stayed a day and headed home. BTW its a cool city but the people are the strangest ever. I took I-35, 287N home and discovered my rigs max speed was 77 mph. The fastest I got up to on the way down was 70. Averaged 7 mpg on the way home. I know this is kind of long and pointless but is this how a stock 7.3 behaves?

Sounds like that truck has an issue...

I averaged 12.5mpg in my 93 towing a 6000lb trailer and with loaded utility boxes, weighed in at around 14,000 gross. Bone stock truck with 280k. If you look around on here most guys are getting better than 14 towing, so I would say it is safe to say you have a problem.

It is a school district truck so there is no telling what somebody messed up. They told me it was like this since day one. What could be wrong with it? Its not my truck but im still curious:w2:.

it knew that it could never compete with your dodge so it didnt even try.

Could be a hundred different things... Could be a tired fleet vehicle that has had too many different drivers who didn't give a rats rear about it. Could be lack of maintenance...

I would say it sounds like a typical 7.3 I routinely got 6 to 7 mpg with a 99 7.3 pulling now with no trailer it could get close to 20 on a long trip.

I would bet low boost from leaking up pipes, dusted compressor wheel, oily boots...

I bet the truck was not making 10# of boost the entire time.

Remember all you cummins haters, the 99 Cummins came with 225hp... Same as the 99 PSD...

Now that you mention it, the boots are spewing oil everywhere, looks like a bad oil seals. International told our foreman that boots leaking oil on any of their Navistar engines is normal behavior. The turbo whistle wasn't very loud either. To all the Cummins lovers, I would take a 7.3 any day over a vp 24v or commonrail just because a 7.3 is more reliable. VP 24v's eat $1K pumps and commonrails meltdown whenever wherever.:w2:

A fleet truck, I would bet it was dusted also.