Jim Shulmister

I put the 98.5 hx35 turbo on and the gov spring in about three weeks ago. I turned the full load screw in a bit and then out a bit along with smoke screw adjustments to keep the smoke down. Finally got the two weeks worth of driving in to fill it back up.It was at half of 1/4 tank left, no low fuel light on. It took 22.4 gallons to fill it back all the way to the top of the neck (I dont like it this full because a little fuel leaks from the top of the fuel tank where the big screw on cap is but i had to have an exact reading). Total miles on 22.4 gallons is 471. I could have easily gone to 600 before filling up. This is all city driving with a small 4 mile run each way on us19. 9 miles total 8 lights 4 times a day and light round-de town nightly driving. <br> Readem an weap 21MPG!!! In a 7500lb dually and i aint got no light foot!!!<br> I will be replacing all of our 7.3 dorf diesels at work with cummins!<br> I still have to add my new bhaf and 3.5&quot;/4&quot; exhaust and all i can see is more power and better fuel mileage.<br> -Jim-

Jim Shulmister

BTW- this is with a stock 12cm stock wastegated housing-probably the biggest factor because i have so much boost at low rpms. <br> -Jim-

hvanflee

Ratchet, what trany are you running there? I must be wrong about thinking more boost would mean more fuel? Are you on summer fuel now, or still on winter fuel? <br><br>I don't get anywhere near that for fuel economy :'(

Jim Shulmister

I have a 5-speed, and more boost means more efficiancy. It takes more lost power from the exhaust and converts it to gained crankshaft power.Think of it like this, on a regular car where you have the air conditioning on. It takes horsepower to turn the compresser that cools the vehicle ,a little bit of the fuel is used for this, therefore you get worse fuel mileage. You turn off the a/c and that fuel is now used solely to power the drivetrain and you get further on less.
-Jim-
O and i dont have summer and winter fuel down here in Florida.It either a rainy fuel day or a sunny fuel day, but only once every two weeks now!

powerwagon440

dang!! that is awesome!! i wish i could get close to 15 or so i would be happy!!! ;D

PumpDaddy

Ratchet,<br><br> Don't you run out of boost at the top end? My stock 92 turbo is @ 21-23 psi at WOT. Bottom end is not really a problem with spooling up, but you can tell there is a lag. We went about 200 miles south today to a job and even running 70-75, it still jumped like heck when punched, 90 mph to pass these idiots wasn't a problem

PumpDaddy

Oh, and I forgot 18-19 MPG @70 MPH

Jim Shulmister

Before I did the mods (spring and turbo) I could run up to about 85-90mph max. 90 wasnt something that you wanted to do though because it seemed to really scream for help. Acceptable cruise was 70 (where all sounded nice). A run up to 80 for prolonged periods made me feel like i was overdoing it a bit also. Since the mods though, it runs to 80 rather quickly and feels comfy up to 90 and i havent taken it past 95 yet. I can tell you for sure that after 65-70 the fuel mileage will take a dump though (Smokin a little) and at 90 (smokin alot more) I would bet the fuel mileage would probably go to 12-14 (estimated). My around town driving never gets above 65 and I believe that maximum fuel mileage would come at this speed. I would guess that at 65mph cruise I would probably get 23-24 mpg, but keep in mind that my truck has only 45,000 miles original so far on the ticker. I would have to do something about the wastegate and exhaust/intake system before the higher cruise would become more efficiant because it is at these speeds that the boost gets limited, but the fuel keeps coming (hence the smoke).When you run the truck up in rpms from 3rd gear on you can see when the boost reaches peak in the rear view. Nice and clean and then poof. Anyways, the top end is much better, but definetely limited by the amount of available boost.<br> -Jim-

Bluebird

I consistently get 17-19mpg with combination driving, <br>19-21mpg with freeway/highway travel. I have a stock truck that I add fuel addative every other fill-up, When I change the fuel-filter I fill it with fuel conditioner. 65-70mph on highway/freeways.

Bluebird

I consistently get 17-19mpg with combination driving, <br>19-21mpg with freeway/highway travel. I have a stock truck that I add fuel addative every other fill-up, When I change the fuel-filter I fill it with fuel conditioner. 65-70mph on highway/freeways.

Redleg

JEEZ I need an overdrive!

planejane

i realize this is an old message that I am responding to, but...i recently bought a '93 d250 at club cab with 171k on it. it has had the injector pump replaced. however, i am only averaging aboug 15 to 17 in city. i don't drive it all that hard, and have an empty bed. i use it to for work(contractor) but never really have a full load. what should i check to see why my mileage isn't as good as these guys are? the truck is in near new condition, both in, out, and under the hood. heck, it looks like i took it off the showroom floor!<br>any help would be greatly appreciated.

Puke

My guess is that your mileage is normal and correct, and that there is a little bit of exaggerating going on in posts.<br>I've had more people tell me they got over 20 mpg. than I can shake a stick at. But when I talk to people who keep a consistent log, rather than the regular bullshitters, , the mileage has NEVER been 20, once in a while aproaching 19 on highway onlyh with no load.<br>I am a contractor and in town get around 15 mpg. (generally have around 1000 lbs. of tools in the back.) I could squeeze 18 or 19 out of it on the highway if I really kept my speed down where it belongs. And I think I am in the more normal part of the spectrum. My brother told me his 1 ton crew cab powerstroke got 24 mpg. and I just laughed at him, because I remember a couple years ago when he told me it got 14 mpg. Funny thing is that he didn't remember because he wanted to believe his own ********.<br>Later, Puke<br>Anway, later,<br>Puke.

planejane

Yeah, Puke, I think you're right. I used to own a powerstroke 2k1 4x4 and it never got better than 17. I realize some people do achieve higher mileage especially depending on where you live, how you drive, and where you take your rig. I am more than happy with the mileage and the truck. Wouldn't trade it for nothing! uh, except for a 2k3 maybe?!

wannadiesel

Planejane-
Puttin' around town in my truck (no fuel or boost mods yet :'( ) I get 16 to 17 mpg, so you're doing fine. Sure beats the craptacular 9 mpg my '85 3/4 ton got, though!