22mpg is nuts. i run 100 rpm less then you do at the same speeds and cant top 20. 19 is a sole stretch and thats sticking to 55 mph

 

how in the heck are you gettin' 100 rpms less than me at the same speeds if you have 4.10's!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!! cody's truck has 4.10's and last night we was running like 2400 rpm's at like 70 or something like that. i can't remember exactly, but the rpm's were way up there!!!

 

i have lots of new pics and videos i am loading now, remember i have 315\75\16 tires.....

 

here you go, most of my overdrive speeds and rpm's are accounted for in this clip
http://youtube.com/watch?v=1EEB2XBB_Wc

 

not to far off from mine, i used to have 315's and thats exactly what i saw. i just cant see how you do that good on fuel with a lift, 315's and 4.10's. i got my superchip on tow mode, whats yours on joe?

 

Reading your very first post, I wonder if your EBPV is not functioning quite properly. There is a sensor tube that may be plugged, causing the hissing, it affected my truck in cold weather but did not affect in warmer weather. At the base of your turbo there is a plug, two wires going in to it, unplug it and see if the hissing/loss of power situation that you noticed goes away, my EBPV stays unplugged forever. Also I am going to run a test, but (hate to open this can of worms) but bad mileage at higher speeds has more to do with aerodynamics and parasite drag (drag created from non lifting surfaces) than RPM's. In other words, 55mph in 4th gear, will give you better mileage than the same RPM in fifth gear at whatever speed it gives you. Of course 55 in 4th will be slightly worse than 55 in 5th, however the percentage gain (I believe, however not proven) will not be as great as the higher speed/higher drag scenario. All drag charts begin to show all of thier drag coefficients increase significantly in the 45/60 mph range. Peace Out.

 

where is the ebpv i havent realy looked at much on this truck yet other than check the fluids, but im defently getting worse millage, i used this truck last summer to tow an heavly loaded 20 ft enclosed trailer, the last 3 days iv been towing an 4 foot shorter enclosed trailer with slightly less loads back and forth 200 miles a day 99.8% freeway and iv been avarging around 10 mpg. last summer when i used this same truck with more load i was getting 13-14 mpg driving the same speeds on the same freeway with the same truck.

 

Here is 2 thoughts/things.

1- The oem tach is not accurate thruout the angle. Dont remember +/- %
also will vary from truck to truck. (mirror of CPS)

2- With stock tunes/trim the PSD is most fuel efficient at 1450rpm.
(light load)

Bill

 

After reading all this I'm surprised I got a little more than 17mpg on my 450mi round trip last weekend. It was all open road, running empty w/ a camper shell and cruising between 75 & 80 most of the way. Some hills and turns, but not too bad. Truck is 5spd w/ 4.10s. Temperature was never above freezing and the temp gauge needle was barely touching the left side of the "N" in the normal range. I checked my speedo accuracy w/ my GPS when I got the truck in '98. With stock tires the speedo was reading slightly over. Now with 285s (33s), the speedo is dead on.

How much does the lack of a camper shell affect mileage with these trucks?

One thing I found out two summers ago when hauling my Bronco ~ 16,000lb total wt w/ spare parts, extra fuel, tools & other junk. I get the same mileage no matter what speed I drive. I made two trips 6 weeks apart to Silverton, CO for 4 wheeling. The first trip we cruised at 60/65 because someone in our group was towing w/ a gasser and it was all he could do. The second trip was just 3 of us in my truck and we cruised 70/75/80. On both trips I got about 11mpg. How is that possible? I would have figured I'd get better mileage at 60/65.

I usually get about 16/17 around town. The best mileage I ever got was between Flagstaff and Abq - 300 miles w/ a 60mph tailwind. I got 22mpg.

 

I usually get about 700 miles out of my gal before I have to fill back up. That pretty much running the first tank almost empty. I think right now I'm getting closer to 15 as I have a ton of idle time.

Before I replaced my injector o0rings i was getting over 800 while I was checking fields and such. That was with maybe 50 miles down the highway at 60.

 

i hate my truck i only get 400 to both tanks, and i run her till she gets past the red "E" line.

 

I put a new downpipe on recently and I noticed that hissing sound occasionally. Is that my EBPV shutting? I thought it was only supposed to do that when the truck was in idle. My mileage has been much worse lately also. Maybe it's just the colder weather. I typically get 21.5 on the highway consistently and I keep the truck at 2000 rpms.(about 71 mph)

 

Yep, that would be the EBPV

 

Is it supposed to open when driving or is it totally dependent on the outside temperature?

 

where is the ebpv valve located?...i feel like an idiot when it comes to these 7.3 powerstrokes as i havent messed with meany of them