Ford Power Stroke Nation banner

1 - 16 of 16 Posts

·
Registered
Joined
·
173 Posts
Discussion Starter #1
i have a 1999 ford super duty ex cab short bed 4x4 it has 373 gears and an automatic iv tryed taking it easy driving it hard it gets the same all the time i need help would have thought i wouldv been getting at least 18 the truck aint that big to start with if anyone has any ideas on how two help please let me know.:confused:
 

·
A Ghost these days.
Joined
·
1,017 Posts
First fill out your signature. List mods and we might be able to help.

I'll start with the basics. Change your oil, Check you air filter, tire pressure and make sure you don;t have a break caliper dragging. Hold old is you AFT is your tranny slipping?
 

·
Registered
Joined
·
173 Posts
Discussion Starter #4
the only mod i have hav is an edge evolution but even wen it was stoke it got the same my tranny works perfect on the tire pressure wat would u suggest on tire pressure?
 

·
A Ghost these days.
Joined
·
1,017 Posts
I'd follow the tire pressures on the side of the tire. Then adjust down a few PSI to make it ride the way you like. I'd recommend that you dump the edge and got with a custom tuner and you should get better fuel economy. I this you need to look @ your engine oil. When did you change it last?
 

·
Registered
Joined
·
173 Posts
Discussion Starter #6
i dont knw wen it was changed last i just bought the truck a month ago but the oil looked almost gold it does have a junking orileys oil filter on wat would be the best oil for me to put in it?
 

·
A Ghost these days.
Joined
·
1,017 Posts
Well make sure it's diesel rates. I personal like full synthetic 5W40 but 15W40 will work in most moderate climates in winter.
 

·
<----Colin Banks
Joined
·
3,001 Posts
Drive it around for a while and get it warm. Make sure you have the Edge hooked up and look to see what you EOT is. That is the engine oil temp. That will help with what Bill said.
 

·
Registered
Joined
·
4,955 Posts
I think mine is also. I might pick up a 203 T stat. 12-13 mpg in town only DP 80E tuned, AFE II, 4" Turbo back. However, most of my trips are less than 10 miles. That probably has a big effect on things.
 

·
Registered
Joined
·
140 Posts
Have you looked at the brakes... maybe a dragging brake....

Even hauling loaded down I always got above 10mpg in my 99, and it was a F350 CC SRW with a 6" lift and 37" tires..

It isn't a Lariat by chance and your looking at the overhead computer for your MPG's???

Also on the slightest chance... have you checked the tranny for slipping... try hooking a load on it and get up to speed... when my tranny started going it would drive around town and even on the highway without any notice of a problem... just a slightly lower MPG... but when you tried to haul any sort of a load with a trailer..... it would slip so bad that you couldn't get over 40mph
 

·
Junior Mint
Joined
·
2,461 Posts
The earlier SDs all took in a good amount of air thru the fuel pick up lines running from the tank all the way to the motor but especially up to the fuel pump. This is entrained air and hurts performance, mpg, etc...

ITP use to sell some fuel tank pick up kits for about $50 that would clear a lot of this up. When I added this mod when I first bought my truck I picked up a solid 2 mpg and it ran so much smoother.

The other big issue is injectors. Your's are old and entrained air adds a lot of wear. Rebuilt injectors on a diesel is about the closest thing you can get to a "tune up" on a diesel.

W/ a proper fuel system, rebuilt single shot injectors, a good chip (DI or DP only), a functioning tranny, and a clean filters, that truck would get 16+ all day long.

Good luck.
 

·
Registered
Joined
·
140 Posts
Suns,

I believe he ITP still has the kits... you just have to order it without some other part to get it for around the $50 mark... It was the first mod I did to my new truck when I got it..... The ITP kit is the full intank and fuel line replacement up to the fuel pump.
 

·
Registered
Joined
·
173 Posts
Discussion Starter #15
i will check in on that itp deal for my tank and i check my engine oil tempeture it runs anywhere from 165 to 185 degrees.
 

·
Moderator
Joined
·
1,097 Posts
Couple of things to check.

Jack up the front end and spin the wheels. They should spin freely. Tow things can happen that would knock your MPG in the head. First the hubs may not be disengaged. Second the front brakes may be dragging. These sintered metallic brake pads are subject to edge corrosion. Corrosion makes the metal expand and cause the brakes to drag. Normal brake wear won’t remove the corrosion from the edges of the pads. In either case, you’ll know right away.

Second, check the front end alignment. These trucks can get some subtle wear that is hard to notice on a day-by-day basis. Out-of –alignment (especially excess camber) will cause the tires to scrub and that is a drag to MPG.

One last thing: Lie-o-meter and one-tank samples will fool you. A valid MPG test takes at least two (and better four) tankfuls to get a handle on reality.
 
1 - 16 of 16 Posts
Top