MPG woes

[Cheapthrillb2]

Trying to get the good mileage from my 97 OBS powerstroke. I have been getting about 12 mpg towing a bumper pull total weight of about 7000lb estimated. The guy I bought the truck from could get 15-17 from it @ 70mph with the same load.

Only thing done to the truck as of now is muffler and cat are gone. I have a 3" Down pipe coming in on weds. The truck has 3.54/55 gears in it now, kinda sucks with the lack of power from take off and accel.

What else can I do?

 

[wpfd571]

I call b.s. on the 15-17mpg towing most trucks only get that empty. Your about right for a mostly stock truck towing. I think the down pipe will make a noticeable difference. A 4" exhaust and a 6637 napa air intake would be cheap upgrades until you can get a chip. But i really dont see it doing much better than 13-15mpg with a load.

 

[Cheapthrillb2]

I'm not as much concerned with power increases that will decrease reliability. I am still rocking the OE trans in my 97 at almost 230K and the trucks been hauling off road rigs most of its life.

Do the OBS strokes have the same cam sensor issues as the duties do?

 

[wpfd571]

Yea i think so, but im not 100% sure. You could try a new one

 

[Cheapthrillb2]

That was my thought, regardless with the mileage wouldn't be a bad thing to replace it.

 

[Cheapthrillb2]

It also seems that half throttle to full throttle there is no change in truck response while towing, is this normal?

And no matter how I drive the truck loaded or unloaded it NEVER "rolls coal" after the Turbo Valve opens once it warms up. It emits NO visually smoke from the exhuast of any color. I can be full throttle up hill towing my rig and it never emits a thing.

Also I am looking at the cam sensor replacement, is the serial number of the engine on the white bar code sticker on the Left Valve cover? If so mine reads 640006 and the truck production date is 11/97? I want to make sure I order the right cam sensor.

 

[zpd307]

the hpop is like the old mechanical ip. the more miles on it, the less its going to pump. if you replace it, i would atleast go with a 17 degree off of a newer 00-03 7.3. they provide more oil to the injectors, which is a good thing. or you could spring for an adrenaline pump, which puts out more oil than a 17 degree pump and isnt too bad on price. the adrenaline is suppose to add some fuel economy also, 1-2 mpgs is common. i am going to go with an adrenaline, mine seems to fall flat at the upper rpms....and i have 204k on the clock,

 

[Cheapthrillb2]

Purchased an Autometer Pyro today along with a MBRP Downpipe only. Where is the best place to install the pyro temp probe, in the manifold? after turbo? before turbo?

http://www.summitracing.com/parts/ATM-3344/

 

[zpd307]

in the manifold, pre turbo

 

[JLDickmon]

I call b.s. on the 15-17mpg towing most trucks only get that empty. Your about right for a mostly stock truck towing. I think the down pipe will make a noticeable difference. A 4" exhaust and a 6637 napa air intake would be cheap upgrades until you can get a chip. But i really dont see it doing much better than 13-15mpg with a load.

me too.
the downpipe and intake won't do much for your mpg's, but will lower exhaust temps, lending to longevity of parts...

 

[ckelly94]

I just towed my 7000 lb TT over the weekend through the hills of Eastern Ohio with my 99 4x4 PSD and got 13 MPG over 325 miles.

 

[69oiler]

i'm getting 10-11 mpg towing...10-12 is normal towing milage for aq 7.3. that PO was blowing smoke. 15-18 is more a typical unloaded mileage figure.

 

[Cheapthrillb2]

Yeah I get 17-19 doing unloaded DD duties.




Where in the drivers side manifold should I drill and tap for the thermocouple?

 

[Cheapthrillb2]

Well I have gotten the boost gauge installed, the pyro installed, did the cold air intake with the napa filter.

I have the MBRP downpipe, 10 feet of 4" and the Dynomax 4" tailpipe, need to get this stuff installed.

I also dropped the pan today and installed the Sonnax spring kit and a new valve while I was at it.

 

[Cheapthrillb2]

Well I now have a 3" down pipe, 4" straight back to the axle, then a 4" tailpipe up and over.

The DOWN PIPE SUCKED

I also have a leak in the exhaust pipe between the manifolds and the turbo. Once the down pipe was out I could see the black marks around the flange showing the leak. Have to deal with that another day.