SSminnow

I bought my 03 truck couple weeks back, and had 1/2 tank when I got it. I filled up, and have been watching the overhead, and ranging between 16.2-16-8, with about 80% of it in town. I am going to figure out by hand, but thought I would ask how accurate dothe overheads seem to be? Also, how many gallon tank do I have, QC LB DRW? I do have 440 miles with a 1/4 tank of fuel left. Thanks!

mikmaze

the overheads vary a lot in how close they come, a lot also depends on mods. Most boxes will fool the overhead into thinking you are doing beter than you are, in many cases by alot. You are lucky to have a 6 spd, With my simple mods I just got a good fro recent hand calc of 13.5 to thegal, overhead read an average of 18mpg, and I do have the reflash. like most trux that last quarter sure seems to go fast so plan ahead for where your next fillup is or you will end up at the mercy of the greedy..... around me that is an Exxon @ 2.75 a gal. I think you have a 34 gallon tank. Also of importance is stock tire size when it rolled off the line versus what is on it now. Tires not calibrated can throw you off, travel further than indicated for larger tires and again confuse the overhead.

SSminnow

OK thanks for the info. Everythign on my truck is stock, no mods at all, even stock tires. I guess I will see as I plan on filling up sometime tomorrow. See how accurate that over head is once and for all

Herrin811

My overhead WAS within 1 mpg...Last highway run, it was off by 5 mpg

Dodgezilla

Mine is very accurate without any of the fueling boxes on..

ptm600

My overhead is anywhere from right on to 3 mpg off, to the better than actual. Usually 1 mpg better than hand calc.

01350banshee

Same here, very accurate when the Quad box is OFF(not that I can remember when that was ), I got 19.4-20 mpg's. With the Quad box on, I get about 2 mpg's higher. Plan on adding MMO/PS real soon, so I will see if this stuff works as mentioned by many here.

underwoodtransp

I'm sure that you have a 35 gallon tank. The short box ones come with the 34 gallon tank. Also to keep in mind I have put 40 gallons in my 35 gallon tank.

Mopardan

Mine has ALMOST always been .4 on the low side. I am completely stock also. I can get 19.5 mpg, but it seems to drop off over 65-70 mph.

SSminnow

Well, filled up today. And my Overhead was basically right on the money. It had been reading 16.2-16.8, and after a hand calculation I got 16.9. That was mostly in town driving with some highway thrown in. So, after I filled up, reset everything, and made a 150 mile round trip today, and overhead was reading between 18.6 and 19.2, all highway, with cruise set at 68-69 (speed limit is 65). Most of this tank will be drving highway, so we will see if that average stays that high. Either way, 16.9 is better then ANY tank of fuel in my last truck (03 7.3 Powerstroke Auto CC LB DRW) It did have 4.10's however, but the best tank I EVER got on a trip to Arkansas was 16.5 ALL highway and cruise set at 65 TRYING to get the best MPG I could, so I really had to work to get 16.5. With that truck (I put close to 80K in 1 1/2 years on it) around town would net 13-14 MPG, and highway 15-16 MPG with the best like I said 16.5. The 16.9 I got with this truck already was me having fun with my NEW (used)truck. In other words, I was a little heavy on the right foot, testing out the Cummins power if you know what I mean. So, I am pretty darn happy with the MPG and the ride, power, looks, comfort (up front), braking, and such.....I do still like the room inside the cab of the Ford better (of course), but since I ride up front I guess it does not matter (not yet anyways)

gus's 03

see some of my prior posts, on winter fuel ive been averaging about 650 miles to a tank, on regular fuel i average 700-750.

my overhead has never ben off more than .1 mpg vs hand..

SSminnow

700-750 Miles to a tank of fuel? If you ran it empty, if in fact we have a 35 gallon tank, you are getting 21.4 MPG. What are you driving, 50 MPH? I am not doubting, just wondering what I can do to get that much mileage out of a tank of fuel. Also, do we have a low fuel light that comes on? I ran it down to a little between 1/8th and a 1/4th of a tank before I filled up. I added 27 gallons with 458 miles on the trip odo. Is there a low fuel light that comes on?

underwoodtransp

yes there is a low light and it comes on anywhere between 5-8 gallons left. but like I said earlier I have put 40 gallons in my 35 gallon tank. So 750 wouldn't seem that far off at 40 gals avg being 18.75 mpg. No problem there.

SSminnow

OK thanks. You must have ALOT of patience adding that much fuel to your truck. When the pump stops, I can add about 2 more gallons of fuel before I give up

charcoal600

Currently my overhead reading is consistently within .1 or .2 mpg of hand calculated mpg, (stock truck). Before I had the reflash done on the rig the overhead was about 1mph lower than hand calculated. I average around 17-18 mpg, country roads and some in town driving; if I really baby it on the highway I've been able to sqeeze 20+mpg out of the rig.