I am going to Chattanooga, TN today and it is a 75-80 Mile trip on the interstate. I am going to go down on Economy and come back on High Performance and see which one will giuve best mileage on cruise at 75-80. Mileage Before the SCMT was 22MPG on the Interstate at 75-80. I will post my results when I return in a about 3-4 hours.

 

Bet you're using the overhead lie-o-meter if your reporting 22 mpg in a 6 liter...

or there's a great elevation change between the two cities

 

Since it seems I always buck a head wind both ways on long trips; maybe he always has a tail wind? Probably that clean living in TN.

Bob

 

Thanks PSD My truck seems to get better mileage in HP mode but I never compared them. Cant wait to hear from you.

Eddie

 

so what was the turn out?

 

22 mpg hand-calculated?
Don't trust the overhead.
Whats the elevation throughout the trip and your average speed?
Is there a headwind in either direction?

 

22 MPG hand calculated on the I-state in stock. I tuned it to HP on the way down and got 18! On the way back in Econo I got 21-22 MPG. Thats very disappointing that I lost mileage..................

 

Lets hold on and not be ridiculous for a second.
I think you need a reality check..others chime in, please.

First, a stock PSD making 22 mpg stock is a freak of nature. In fact, on a 6.0 it's almost unthinkable. 7.3s have accomplished the task, but not many 6.0s.
Second, no tuner guarantees a mileage gain, but most trucks gain mileage.
Third, your method of testing is VERY loose.

You got 18 MPG in a diesel truck weighting what?... 7500 lbs?...not to mention it has WAY more power than stock.
Did you drive it at the same exact loads and speeds as stock?
Its simply not a good method of testing.

All that set aside, lets 'assume' the mileage numbers are correct.

I don't care if you use the superchips, predator, edge, etc.....18 MPG in a diesel with all of that power is PHENOMENAL!
There are a lot of stock calibrations making 13-15 MPG and the people are enthralled when they pick up huge power, drivability and mileage with a tuner (SCMT, SCT, Predator, whatever).

The programs are only going to make so much mileage, and your gains (or lack thereof) will depend on how fuel efficient the truck was stock.

Your stock tune was very fuel efficient......VERY fuel efficient (to the point where I raise question).

Did you enjoy the extra power? Shifting?

A post like yours reminds me of the guy who gets a pot of silver and complains it is not gold!

Most of us from "the old school" realize that gains in excess of 100HP usually come with dramatic mileage LOSSES.

Basically, you should be happy...but if you are not, I encourage you to enjoy your truck stock as everyone else passes by and waves

 

Oh I am very happy, mileage is not the reason I purchased it. I LOVE IT. The economy mode shifts a little eradic for my liking and it is version 5.03 btw. Its ungodly the power that is made with this thing! I ran a buddy today with an 03 w/ the edge and I beat him. That really made me happy with the choice I made. I love the smoke thats the best part of it as I filled up a ricers cockpit with the wonderful "DOZER DUST." The tests were made all today same amount of miles and same speed I was carefull of that. I set cruise to 77 down and back and did a hand calculation and was suprised to see that the overhead was fairly accurate considering I reset it after both fillups. (Overhead a few points off. Hand CALC was 18.6 and overhead said 18.4) I am not complaining I represented what I said wrong. I was more bumfuzzled than I was disappointed. I had read so much on them giving mileage(once again I didn't expect but maybe 1) that I just thought atleast I will pay for this thing in the long run.

 

think of all the money you'll save on carnival rides.

 

Well brother, I hope I have as much luck as you with my 04. I purchased it while I have been here in Baghdad, Iraq. I still haven't driven it yet but only weeks away. I'm so excited, I can't sleep at night and my buddies are tired of hearing about it.

 

Version 5.03 doesn't have to do with the tuning, it simply is a firmware version.
Let the shifting learn a little...if it's too hard it can be adjusted.

Funny how your lie-o-meter is close.
A lot of members will tell you it's nowhere close to accurate.
It was a REALLY bad problem on 7.3's

 

When I get home in a couple weeks I will be pulling an 18ft dovetail with a 3900lb car 1350 miles. I will get a mileage test for you all. I hope it is good.

 

I definately wouldn't complain! The best mine does stock is 12 city, 13.3 combined and 15.5 @ 70 mph hwy. I miss my 7.3, maybe it had a little less power but at 2.30 a gal I'll take the mileage difference over a little power.

 

Thanks for the test. Oddly mine gets better milage in the HP setting then in economy. I mean 2.5 to 3 more mpg. In the summer I was getting 17.3 to 18 hwy/city in HP and did my own test in economy and got 15.4. I tested two tank fulls in economy when fuel was on the rise. Then I could not waste any more fuel. I also am very pleased with these numbers in HP mode.

Vic,

Do you think that if I got my truck reflashed that the mileage would increase? I have heard many stories of milage droping off from doing this but, with this new flash I have heard just good things with MPG increase?

Eddie