tbirdfiend281
Full Access Member
ya id be curios to know if some addatives help alot, i think you should see an improvement
dismal fuel milage even cruising on highway
- Thread starter 69oiler
- Start date
69oiler
I don't feel tardy
added 1/2 bottle of the grey bottle PS additive today to my full tank. enough to treat 50 gallons.
tbirdfiend281
Full Access Member
let us know the results man
69oiler
I don't feel tardy
11.9 mpg. added 16 gallons of fuel and the other half bottle of power service. tommorow i'll be towing so we'll see if i break single digits.
Russ
Idont do injectors
Rob any chance the brakes are hanging up? I know you've said you've had problems with the frt. brakes. Longer idle times? Speedo off? fuel leak? Just looking for clues.
69oiler
I don't feel tardy
russ i just put all new front brake calipers and pads on. no fuel leaks but i have been running it slow speed off road at the farm i'm working at. maybe almost a mile a day under 15 mph. plus more frequent starts and shutdowns. not much extended idling though. dunno about the speedometer being off, havent seen a radar trailer in a while.
69oiler
I don't feel tardy
13.2 mpg 
towing my dad's 8N tractor on a 14' trailer. i dont get it. towing in and out of OD at about 50mph.
i asked the biddys at the fuel station if they has switched from winter to summer fuel and none of them knew
i dont get it. better milage towing at 50 mph than empty at 70mph?. i guess it has to be the fuel and amybe the additive.
towing my dad's 8N tractor on a 14' trailer. i dont get it. towing in and out of OD at about 50mph. i asked the biddys at the fuel station if they has switched from winter to summer fuel and none of them knew
i dont get it. better milage towing at 50 mph than empty at 70mph?. i guess it has to be the fuel and amybe the additive.
FULL FORCE
Full Access Member
I have a 99 I just bought, I got 14.4 on highway towing an empty 16 ft car trailer last week, truck with no trailer it has been 11-13, I am not sure why, 4X4 hubs unlocked and 250,000 miles, truck runs fine, I just did a full 4" exhaust tonight and have a chip coming, I hope it helps!
I have a friend with a CC with similar miles and he has the exhaust and chip and averages 16-17 with winter fuel.
I have a friend with a CC with similar miles and he has the exhaust and chip and averages 16-17 with winter fuel.
tbirdfiend281
Full Access Member
chip makes a big difference with the fuel trims, its like my tbird, even with the 3.73s it can still see 26-28mpg cruising and 19-24 around town, but without the chip it was down 2-3mpg then what im geting now
it could also be related to the 20mph difference in speed. aerodynamic resitance can increase exponentially depending on the shape of the truck, so maybe try unloaded cruising around 50, see if it goes up, but then again maybe the addative helped
your guys miledge seems really low though, my 6.9 without o/d could get a best of around 16 or 17 cruising, and it was going 60-75mph usually, all it had was an exhaust and a pump running more fuel, so the newer di motors getting worse then that is wierd
it could also be related to the 20mph difference in speed. aerodynamic resitance can increase exponentially depending on the shape of the truck, so maybe try unloaded cruising around 50, see if it goes up, but then again maybe the addative helped
your guys miledge seems really low though, my 6.9 without o/d could get a best of around 16 or 17 cruising, and it was going 60-75mph usually, all it had was an exhaust and a pump running more fuel, so the newer di motors getting worse then that is wierd
69oiler
I don't feel tardy
yeah my 6.9 always got 14-17. i dont remember it ever dropping below 14. 3.55 gears 4 speed manual trans.
last summer this PSD got 16-18. i have since added a cap with a ladder rack on it. that probably has something to do with it. going fron 235 to 265 tires also probably had something to do with it. still a lot of guys with 3.73s and auto trannies are getting mid teens.
here's the truck.
last summer this PSD got 16-18. i have since added a cap with a ladder rack on it. that probably has something to do with it. going fron 235 to 265 tires also probably had something to do with it. still a lot of guys with 3.73s and auto trannies are getting mid teens.
here's the truck.
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tbirdfiend281
Full Access Member
ya thats what ive been hearing mid teens for 7.3 trucks, i think your about normal, and i think with a good fuel addative it may increase a little bit, but i guess you will have to play around, be careful though, i would hate to see your truck get a contimination problem
h2odrx
Anti-O
that thing has a 7.3 in it? front clip been replaced? v8 tag? i've seen that alot is it cheaper or what?
Russ
Idont do injectors
The early 99's had the powerstroke V8 emblem on the front fender After that the Powerstroke emblem moved to the door minus the V8 part
69oiler
I don't feel tardy
Russ is correct my truck was made in 9/98 and these early Superduties are oddballs. there's a few weird things about them which is what they are called "early 99s" the fender sticker is the easiest way to tell if it's an early 99 but there are other differences such as the front wheel bearings and the turbo i think and some other stuff. Nick will tell ya if he sees this.
on another note with the nice weather we have had the last few days i have been rolling down the windows, locking out OD, and taking the scenic roads home and blasting up the hills. nice to drive with your window down after a long winter.
on another note with the nice weather we have had the last few days i have been rolling down the windows, locking out OD, and taking the scenic roads home and blasting up the hills. nice to drive with your window down after a long winter.
Russ
Idont do injectors
Rob do you have auto or manual hubs? 4x4 may also be part of you MPG issues?
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