Poor Fuel Mileage

[Archive]

I recently purchased a 1996 2500 Ext Cab 4X4 w/ 3. 54 gears. It has a new air filter and looks to be completely stock. The truck runs pretty good although a bit of a dog on the low end. My fuel mileage is between 13 and 14 MPG. This genuinely sucks ! Everybody I know with the Cummins gets around 20 MPG. Any suggestions ???

------------------

 

[Archive]

Could be that your timing is off,good place to start anyways.

------------------
95' 25004X4,AT,Driftwood,Banks,Warn fender flairs and running boards(Play truck)95 3500,5 speed,driftwood,Banks&phscotty,34,000 GVW apple and tractor hauler(work truck)

 

[Archive]

I have a '95 single cab and have been getting almost the same milage(post bombing and pre bombing / before and after bigger tirs also). it has gotten slightly betterscince i got it retimed and the valves readjusted. I have only run 1 tank fo fuel scince the valves, and I got 14. 534mpg out of it(that is not adjusted for the tires). I am going to get the 370hp injectors very soon for more power and to hopefully increase my milage, because that is the next thing I have been told to check.

If you get yours figured out let me know, so we can both be with the majority who are getting around 20.

Good luck,
Scott

------------------
'95 2500HD, SLT, White, 4x4, 5-speed, 3. 54 LSD, 4"JRE, 270/675 JRE plate, leveling lift waiting at work for a new track bar... more BOMBING to come!

 

[Archive]

PSI,a couple more things, since you say your truck is a stock '96 I wouldn't be surprised if the cat is on it's way to plugdom,get rid of it. You should also invest in pyro and boost gauges,they are essential for montoring your engine.

 

[Archive]

Wasn't it the last TDR magazine where they discussed horsepower/fuel economy expectations? My 95 regular cab gets 20mpg. If I remember the article right, you can deduct 2-3 mpg for 4X4, 1-2 for extended cab... hmmmm, hate to say it, but that is already getting us down close to what you're getting. Does it have oversized tires? If so you can knock off another couple of miles per gallon. Illflem is definitly right, ditch the cat asap. A cat on a diesel is a bad joke and nothing but an inevitable problem.

[This message has been edited by danandme (edited 08-20-2000). ]

 

[Archive]

My 97 extended cab, 4x4, 5spd regularly gets 21/22 mpg. I get 14. 5/16. 5 pulling my 5th wheel.

------------------
97,ext cab,4x4,5spd,US Gear box.

 

[Archive]

I have a '93 and it has always got 13-14 mpg while I have owned it. That includes when it was stock, after the Banks Stinger Plus kit, after the pump was rebuilt (stock), after the new Power Wagon Injectors/advanced timing and after me fiddlin' with the fuel pump. The gal I bought it from said she got 16 mpg towing her horse trailer to Oklahoma. Almost all my driving is moderate/severe stop and go and I do squeeze the throttle (it's fun!). My on highway rpms are about 2500 with 4. 10 gears at 70 mph. Boost is at 10-15 psi so I am not surprised at my mileage at all especially after reading TDR issue 29 about the BSFC curves. If I drove highway at 55-60 mph, 2-3 psi boost, I think I could get 16 mpg but my foot can't do that #ad


I tightened up my AFC diaphragm spring and I've noticed my mileage is a little better (. 5 mpg) even though the pump is set pretty high for full load and boost fuel rate increase.

------------------
'93 W350 Club Cab, Bright White, 5 sp. , 130K, Factory Options: Bucket seats replaced with factory split bench, LE, 4. 10, Limited Slip, 7600 lb. rear springs, tachometer, front stabilizer bar. Mods: Banks stinger plus, Linex bedliner, 25,000 lb gooseneck ball, 10,000 lb receiver, Tekonsha brake controller, POWER WAGON injectors-WAY faster than stock!.

 

[Archive]

Plugged up catalytic converter maybe. I have the same truck and have always averaged about 20 MPG on the highway.

------------------
'96 2500,4x4,CC,5spd,TST 280hp plate & AFC kit, Banks cat-back exhaust, Pyschotty air.
Amsoil Bypass, Rancho RS9000's' Westach combo guage.

 

[Archive]

I have a '94 4x4 2500 auto with 3. 54's and get 13-14 mpg ALL the time. I have scotty air and a straight exhaust. I have already added the 370's. The injectors didn't help mileage at all. I just bought new tires to get away from the 305/70's that I had. That doesn't seem to have helped much. I think some of us are just unlucky.

-Chris

 

[Archive]

Cruise control, solo, @70, all hwy & I'll get 21. Commuting & town driving with some playing, 17. 5 lowest to mid 18's.

------------------
Money Sink - 96, 5 speed, Injectors, 280/685 & AFC housing slid.
4" CAT back & CATless, 4" chrome turn down straight out back.
ISSPRO Pillar, Delvac 1 & Amsiol, K&N, Monicas silencer ring removed, Exhaust brake, Mag-Hytec, 3:54, 235s.
HX35s days are numbered, HX40-16 is here.
Un-Bombed = Boring

 

[Archive]

I got 21 to Ohio and back, averaged. I'm the guy you see at the pump for 1/2 hr squeezing in that last drop!
Speedometers are not as accurate as you'd like to think. This could be it...
Much has to do with driving habit too. When I went to Ohio, my Dad drove out and got 21. 75 mpg with a headwind all of the way.
I drove back, I got 20. 4 mpg, with a slight tail wind?? I was keeping between 70-78 mph. Dad drives at 65-70.

------------------
98 Quad cab 4X4 2500 12 valve,5 speed,3. 54 rears, 8' bed. Boost and egt gauges but basicly stock. 55,000 Mi as of 8/21/00.
NRA life member. High power/IDPA.

 

[Archive]

Oh yea, illflem is right about the cat. I'm overdue to gut mine.
I was an owner operator for over 10 yrs. (class 8) they tried to make a cat for the big trucks way back when. They were a miserable failure. Imagine a cat as big as the back of the cab!!

 

[Archive]

What brand of fuel do you use. I run Texaco or Cenex fuel and get 19-21 depending on how I drive. I did try Conoco from a local gas station that uses some diesel but no semi's fill up there and I got about 15 mpg.

Mac

------------------
95 Ram 2500 Auto Std Cab, Cat & Muffler Fell off, 125,000 miles.
Bombed-to-be!

 

[Archive]

Originally posted by danandme:
Wasn't it the last TDR magazine where they discussed horsepower/fuel economy expectations? My 95 regular cab gets 20mpg. If I remember the article right, you can deduct 2-3 mpg for 4X4, 1-2 for extended cab... hmmmm, hate to say it, but that is already getting us down close to what you're getting. <<<<Does it have oversized tires? If so you can knock off another couple of miles>>> per gallon. danandme whay do you say you can knock off a couple more miles per gallon with over size tires. It was my understanding from answers to my post a while back that one had to add milage when running over size tires. Would that not make for better miles per gallon.


------------------
95 3/4 4x4 5 Spd K&N Air Filter 100,000
Ride Rite Air Overloads
10 1/2 Cabover Camper

 

[Archive]

RCMC, I was using the fuel that has sulfer in it for a while :rolleyes (I know the law, so please spare me)
On my last trip I was buying from truckstops. No specific brand.
In the past I got it delivered to my house #ad
#ad

It smoked a bit more with "house blend" but it ran fine, got better mileage, and was quieter. However I know my cat is shot now !!

------------------
98 Quad cab 4X4 2500 12 valve,5 speed,3. 54 rears, 8' bed. Boost and egt gauges but basicly stock. 55,000 Mi as of 8/21/00.
NRA life member. High power/IDPA.

[This message has been edited by The patriot (edited 08-26-2000). ]

 

[Archive]

patriot,Ruby shot my cat also. 27 mpg has been the best,pretty good for an AT 4x4,eh?Hate the sound and smell of the clear,only use it if I have to.

 

[Archive]

You did not indicate if this was highway or city, if it is city (alot of stop & go) and being a 4x4 this is pretty typical mpg.

If this is hwy and your running 60-65, consistently and your getting that low of mpg, there is something wrong.

I average 21+ mpg hwy and 13-15 mpg in the city and 12-13 mpg towing a 10,500+ lb 5vr. I do run a fuel additive every other tank.

------------------
Terry S. '98. 4 Quad Cab SLT, 2WD, 12 Valve - the correct number! 3. 54, AT, Trailer tow PKG, Camper PKG, OEM cab lights, 4" exhaust turndown, 5th W. Hitch, roll-top bed cover, tint, high performance K&N air filter, 265 Michelins and turbo silencer ring in the tool box!

BOMB'n in Tacoma, WA.

22,300 miles - 8/13/00

 

[Archive]

If the prices ever drop, I'll get another load. But for now it'll have to do with the pump stuff. #ad

For some reason I seem to do better "around town". Probibally because this is mostly a steady 40-50mph. Highway speed (high rpm) nock it down a few mpg.
Best I ever did was just over 24 !!That was commuting to/from work. 35 miles each way, 4 traffic lights on the way, 50 mph riding.
I used to regularly get 700 miles out of a tank, but now with "pump fuel" and I messed with the spring setting on the fuel delivery delay (8mm hex screw. Forgot the name of it) I'm hard pressed for 550 !!!!
I've been using Howes fuel additive and I thing it's helping.
PS illflem, 27 ??? I'm jealous !!

[This message has been edited by The patriot (edited 08-26-2000). ]

 

[Archive]

If I don't try to beat everyone off the line and out accelerate them to whatever speed, spinning the rear wheels in the process, then I can get 18. 5 in the city. Most of the time I get 16. 5-17. 5.

On the open road if I don't have a headwind, keep it around 60-65 and turn the A/C off I have gotten 22. However running 80 with the A/C on I get around 17. 5

'96 2500 4x4 Stick -AGR (ARG?)wheel turned all the way in (oops)

 

[Archive]

Oh yea, thats the AFC wheel turned all the way toward the engine (I need to back that off) and 3. 54 gears.