[HEAVYHITTER]

I posted this in the 7.3L general section too.

So just got back from a trip from Portland to Salt Lake and back towing 5,500 lbs w/ the 7.3L Ex. Now on the way down going 65 MPH, RPM's under 2K unless there were big hills I got about 11-12. On the way back we were less about 50 gallons of race gas in the trailer and granted there was a head wind but I got a whopping 8.5MPG, driving the same. Does a head wind really cut economy that much?

Does this seem abnormally low? It sure does to me. I couldn't imagine a gasser if I got 8.5MPG w/ my 7.3L. Or what are the big rigs getting 2MPG?

It seems to be running fine. I have the stock programming in my truck and was suprised to see it pull 19 touching 20 for boost while pulling a big grade. I have a straight pipe MBRP full turbo back and just put a Ford AIS in before the trip. Going over the pass I hit about 1200 degrees EGT max without letting up.

So at this point towing I would say I did better w/ my 2003 F250 w/ the 6.0L a lift and 35's....This seems weird to me really.

Input? 8.5MPG? I really thought the 7.3L was suppose to do better than this under the same driving conditions.

Thanks

 

[Benjoman]

C
We have the same truck. Mine is bone stock except for suspension. I just did 5500mi. trip towing my 6000lb TT from S FL to Las Vegas and back. I did notice headwinds to be quite significant would drop me from high 11s to mid 9s mpg. Speed was between 60 and 70, mostly 65mph. Overall on the overhead computer I got 11.4mpg. That includes a few hundred miles without the TT. Around town in Las Vegas etc. Did the headwind keep you out of OD a lot. That would definitely push the mpg up.
Ben

 

[turbodave]

Depends on how bad the head wind was, but if it was brisk, it can make severe cuts in your mileage.

 

[Mudraga]

You didn't say what you were towing. But if it was a box trailer or something with a big front profile, that doesn't seem strange to me at all. Towing my bronco on a flat bed (~7k - 8k total) I've gotten as good as 13mpg. But towing a mostly enclosed stock trailer, that weighs only about 2500lbs, in a good headwind I've gotten as low as 10mpg. I think wind DRAG makes a huge difference.

 

[Graupp]

AGREED!!! It's the wind!!!!

The speed at which you travel increases the kinetic force..

Wind is just a multiplier, off-setting speed

I've done some reading , here on the TDS, about different theories,

and even considered a "GEAR VENDOR" to change ratios....

Bottom line, you're still 'fighting' the wind resistance...

I get 10-12 mpg towing a 10K TT, doing 60-70 mph..

A chip "might" help, but then you've got the egt's again!!!

I talked to an 18 wheeler VOLVO driver, one time @ Valero truck stop.
He said he got 6-8 mpg, but he's running 1500 ft torque [?]

Running solo, with rpms under 2000, I get 22 mpg...

Drop it down under 60, and it's 24+

We did a 3500 mile solo road trip last fall, running 65-80 mph, and average 18.5 [calculated].... /ubbthreads/images/graemlins/smirk.gif

GIVE IT A LITTLE MORE TIME... /ubbthreads/images/graemlins/eek.gif

 

[dougger222]

I only made one trip towing around 5-6K lbs with the X and averaged around 14 mpg on a 900 mile flat trip. Kept speeds around 65 mph, 3.73 limited slip. Small car on a 20ft 2,500 lb pound flat bed.
Wind can really make a difference towing especially with a large flat front trailer. Wind makes resistance just like going up a hill and getting 3-5 less mpg than going on flat land.

 

[HEAVYHITTER]

You guys are right the wind truely was the biggest factor to the dropped economy. It was a box trailer and unfortunately an extra height one at that so I agree its like pushing a brick through the wind and then some.

I filled last night after dropping the trailer and the truck feels sooooooo much lighter /ubbthreads/images/graemlins/smile.gif

I reset my mileage computer just after the fill while on I-5 crusing at about 60 MPH and it was reading mid 20's until I got into the in town stuff.

So what I thought was weird and impossible is the fact that my X pulled 19+ on the boost gauge. I thought 17 was it for the 7.3L.

 

[Mudraga]

[ QUOTE ]
So what I thought was weird and impossible is the fact that my X pulled 19+ on the boost gauge. I thought 17 was it for the 7.3L.

[/ QUOTE ]

Stock maybe, but you've got a good exhaust and better flowing intake. Even with my minor mods, I hit over 25 easily when I want to.

 

[alramsay]

My two cents. I tow a 28ft TT at about 8K lbs. Got 14-16mpg at 68 mph/2K rpm. All stock on the truck. Just clean air an fuel filters. They seem to all be a bit different though. I've talked to guys getting 20 & some getting 6. Too many variables to count. Good Luck.