mileage

[2shus]

I am new to the dodge diesel pickups, have owned mine about 3 weeks, its a 95 2500 4x4 automatic with leer cap, 110,000 miles on it and i'm unsure of the ratio but i know its a posi trac setup, it is all stock i believe other than a manual torque converter lockup switch under the dash. It still has catalytic converter on, it runs good and has plenty of power. My question is: its only getting about 14 MPG on the highway empty and i see on this forum where guys are getting 19-20 MPG with the same setup and i've heard they get a lot better normally. What am i doing wrong and are there any simple modifications i can do to improve MPG? I am mechanically inclined but the diesel thing is all new to me. I would appreciate any advice from experienced owners and feel to email me personally if needed, Thanks: 2shus@gibsoncounty.net

 

[Missouri Mule]

2shus,
Driving habits(right foot articulation).
Rear end ratio should be on the label attached to front inside of hood, also gives a list of some options or label on rear dif. I would try hood first. If you have anti -spin rear(limited slip)it is probably 4. 10 rear. The 4. 10 rears will get less mileage than 3. 54 rear similar vehicles. 4wd will get less mileage than 2wd.

But lets say you are getting less mileage than normal.
Start checking everything and anything with fuel system and then air intake system.

Start with easy things first, such as fuel lines(rubber) especially the return fuel line, this line is known to crack from heat of engine and unless previous owner changed it out it could be leaking. (Return fuel line is located behind fuel filter and partially injector pump(attaches to metal lines behind injector pump and transmission bell housing. )
Lift pump(fuel pump) below fuel filter.
Make sure fuel filter has been changed recently or not filthy (know of a guy bought used Dodge/Diesel after a month no power and filter was black, hadn't been changed for a while).
Out of time (injector pump).
Air intake system make sure your getting plenty of air for turbo and all hose clamps are tight.
There are a few adjustments you can make which mite help, or if adjustments were made re-ajdust to stock settings.
Of course when all checks out you can always bomb. Have a nice day. If I forgot anything one of the other members will remind me.

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Bill Thomas
Missouri Mule - 96 Wht 4X4 ST CC,5 spd, 3. 54, 8 ft bed, 1 ft high cheater boards.
99 Freightliner bl/wht FL60 ISB-5. 9 24v,215 hp,520 tq,6 spd, 3. 59 nsr,16 ft box, 19. 5 tires,Wt/gvw 11,000/23000

 

[2shus]

The fuel filter and air filter have been very recently changed and the fuel lines have been replaced but i triple checked for leaks. Please explain the different ways to bomb. The sticker under the hood says 3. 5 gear ratio. I drive truck very moderately and have a light right foot, any other suggestions? Thank you for your info.

 

[illflem]

With as many miles as your truck has I would think that the cat is clogged or close to it. One thing for sure is that it isn't helping emissions whatsoever. Lose it first then see where that gets you. You may also want to check the prefilter located in the fuel heater for plugging. My 2500 is the same as yours, it gets 22-24 mpg @65 mph empty on the flat consistently.

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95' 25004X4,AT,Driftwood,Banks Stinger,Warn fender flairs and running boards(work truck)
95 3500,5 speed 3:54,BD E-brake,Driftwood,Banks&Psycotty,34,000 GCVW apple and tractor hauler(works harder truck)

 

[DieselB59]

You have to start eliminating the basics first.

Fuel filter--change it if you don't physically know when it was last changed->and don't trust written records
Valve adjustment--when was it done last; if ever
Timing--Injection timing is everything in our pickups. Being one or two degrees off can affect timing drastically.
Trap Oxidizer (catalyst)--As Illflem stated, when clogged or broken apart it does more harm than good.
Tire pressure and alignment--as nitpicky as it sounds, if incorrect, can lead to bad fuel mileage too.
Amount of time spent on the loud pedal is my biggest fuel mileage suffering. It's amazing how much you can save if you just keep the revs down.

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Chris Timochko
AUTO WURKS DIESEL R&D TEAM
1997 5sp 4X4, Rhino Linings, Espar Heater, A. W. D. HX40 turbo, ATS 3pc Manifold, BD 4" Brake, Marine Compression, A. W. D. Custom Tuned Injection Pump, A. W. D. Intercooler, A. W. D. 370B Injection Nozzles, Delivery Valves, Governor & AFC Spring Kit, Psychotty Air, A. W. D. Water Injection, NOS Diesel Kit, A. W. D. 6" Chrome Exhaust System, BD No Smoke Valet Switch, McLeod Dual Disc Clutch, Mag-Hytec Rear Cover, Cummins Chrome Kit, Optima Red Tops, Hadley Bully Horns, Hurst Line Loc, Goodyear Wrangler AT/S 305/70/16s. 15. 50@97mph on Goodyear All-Terrain tires.
****************************************************************************
Project U96 - 1996 3500 2WD racer. A. W. D. Marine Ultra Low Compression, A. W. D. Teflon-coated Pistons, A. W. D. High Lift Camshaft, Ported and Honed Cylinder Head, Intake and Exhaust manifold; A. W. D. HX40 Turbocharger, ATS 3pc Exhaust Manifold, A. W. D. Water Injection, A. W. D. Custom Fabricated Fuel System, Race Spec A. W. D. /BD P7100 Injection Pump, A. W. D. Custom High Flow Fuel Injection Nozzles, BD Auto transmission and Custom TC, Weld Draglites, Goodyear Eagle Drag Slicks, 5" Single Stack Through The Bed, Mag-Hytec on Rear and Transmission. 11. 54@115mph

 

[fortunate1]

2shus, Chris T. & illflem have given some good advice. My setup is a lot like yours, except for the 4wd. Two other things come to mind that I have tried to keep an eye on: 1) make sure that the filter screen in the fuel pre-heater is clean. It's easy to get at & clean out, but the job is sort of messy with the fuel dripping down your arms. 2) a defective fuel return valve will send too much fuel back to the tank and won't allow enough to enter the P-7100 pump. I've heard of some people taking out the spring and stretching it for a temporary fix. Do a search for these threads. Dirty fuel and restricted fuel & air flow are the leading causes of low power and poor milage. I also 2nd the opinion to replace the cat with an appropriately sized piece of exhaust pipe. You'll definitely free up the exhaust flow. Don't BOMB until you've got everything running well stock; you'll never be able to troubleshoot any problems if you do.

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95 2500 SLT, clubcab, 2wd, longbed, a/t, 3. 54, 145K miles, "all the usual refinements"

 

[BCFAST]

There is a simple equation to keep in mind here. Now that you have eliminated a few obvious faults, this is what you need to remember: Your truck weighs about 6000lbs. Now, which motor works less hard to move a 6k mass... 175hp or 250hp? OK, thats an easy answer... . so, buy yourself a TST plate, open up your exhaust and enjoy 20+ mpgs!

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97 2500 CC 4x4 3. 54 5spd, Green, #12 plate slid all the way forward, 4inch open exhaust, 235/85 Michelins, RS 9000's, PrimeLoc, Red Tops, TDR cloisonae grill badge!

 

[Tom C]

Welcome to Diesels and TDR.

Valve adjustment, New exhaust, might change auto transmission fluid and filter, check for brakes dragging. remove any type of wind deflectors. get away from the winter fuels and retest for milage. you should get 19 with the auto transmission. add a TST plate in and you'll boost power and milage.

good luck #ad


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2001. 5 2500 4X4, QC, Auto, 3. 54 LSD, SLT, SWB, Trailer, Camper & Snow plow Packages, White, 35k# Cody Hitch, 20' Gooseneck Lowboy flat-bed Trailer.

[This message has been edited by Tom C (edited 02-27-2001). ]

 

[2shus]

I appreciate everyones help and info. Thanks for the quick and very helpful responses. I better get busy checking things out though, thanks Tim E. Spade

 

[2shus]

Originally posted by BCFAST:
There is a simple equation to keep in mind here. Now that you have eliminated a few obvious faults, this is what you need to remember: Your truck weighs about 6000lbs. Now, which motor works less hard to move a 6k mass... 175hp or 250hp? OK, thats an easy answer... . so, buy yourself a TST plate, open up your exhaust and enjoy 20+ mpgs!

Hi bcfast and thinks for the info. After i have eliminated any and every possible existing problem i would like to do the TST plate. Where do i get one? What is the cost? How hard for an amateur to install? I am mechanocally inclined but the diesel thing is all new and greek to me. Where is a good place to read up on the TST plate and how it works. Thanks in advance for your help. Tim E. Spade

 

[Heetseeker_1]

2shus,

If you want a source for information on TST products like the 'cam plate', look no further. Performance products are regularly discussed here in the forums. Try a search, as you will have a ton of reading to do. Or, you can try a tstproduct.com search on your browser or go the the TDR home page and click on 'LINKS'. Sorry I can't link you from here, i'm still learning about this site.

You can buy a cam plate from various vendors such as, TST BD DIS or others located in the LINKS area under 'performance' or 'accessories'.

The plate install is pretty easy if you have the right tools and don't get frustrated easy. You can get the instructions from the TST site if you are curious.
I for one would be very carefull using the TC lockup switch when you're on the power going foward. It was designed to enable you to provide some additional braking ability while on steep grades. It will help destroy your transmission if you use it for performance purposes, especially if you turn up the power on your cummins.

Have fun with this site. It's awsome.

S.

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98 qc, 12V, 4x4, slt laramie, 47re slushbox, 3:54 ls diff, 2YG pkg, Kelsey trailer brake control, dodge running boards, diamond plate bed rails, prime designs bug shields, silencer ring wind chime on porch, Raven cab-hi camper shell, psychotty air system, T/C lock-up switch, gutted cat, Walker muffler 22572, crome 5" tip from Kenworth stack, Isspro guages, A pillar 3 guage mount, TST #6 250/635.

Toys: 70' F250 4x4 highboy- 429cid 400+ hp on 35"BFG's(ranch truck) 64' MF 205 tractor 3cyl perkins diesel w/bucket

 

[2shus]

Originally posted by LandShark:
2shus: We have similar trucks (see sig) and I get 19-21 mpg unloaded and 15mpg with the camper loaded. I have a light foot.

I see that you have a lockup switch. . Makes me think that other mods may have been made. Check the anti-tamper bolt on the AFC housing and see if it's been 'tampered' with. Also check the injection pump for safety wired screws and check that area for chipped paint which could indicate someone was BOMBing.

Do a search on 'TST' and 'torque plate' and you'll find plenty of info on these topics. Also, if you don't have one, get yourself the Dodge service manual!

Most of the basic BOMBing mods don't change your mpg if you drive the same. However, they do allow you to drastically lower your mpg with a heavy foot!

I am not sure what the AFC Housing is?

 

[The patriot]

2 shus, this link will give you an idea what's involved with replacing the cam/torque plate, and what an AFC is. http://www.tstproducts.com/power_install.html
You would be best to get the truck running the best you could before you do any modification.
14 mpg does sound a bit low. Try a different fuel station. General consensus is Texaco sucks.
Welcome aboard. #ad

Eric

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98 Quad cab 4X4 2500 12 valve,5 speed,3. 54 rears, 8' bed. Michelin 275 75 16 lr-E. Boost and egt gauges but basicly stock except for a "properly adjusted" AFC. Cat in the garage. Uniden HR 2510, Texas Star 1200 amp. 63,000 Mi as of 1/27/01.
NRA life member. High power/IDPA.

 

[Hogan]

Originally posted by BCFAST:
this is what you need to remember: Your truck weighs about 6000lbs.

This reminds me, I had my truck weighed the other day. '97 2500 CC SLT, 5spd, 2wd, rubber mat in the bed, full tank of diesel, and me (150lbs) in the vehicle, the truck weighed in at 6480lbs. 3780lbs on the front axle alone. Whenever I think about more power, I always remember how much the truck weighs and I don't feel quite the need anymore. #ad


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'97 2500 CC SLT 4x2, B5. 9, NV4500HD, 3. 54s, slid torque plate, no silencer ring
'98 Jeep Cherokee
'47 Willys CJ-2A, 302 v8, auto, 5. 38s, locked and ready to ROCK.

 

[LandShark]

2shus: We have similar trucks (see sig) and I get 19-21 mpg unloaded and 15mpg with the camper loaded. I have a light foot.

I see that you have a lockup switch. . Makes me think that other mods may have been made. Check the anti-tamper bolt on the AFC housing and see if it's been 'tampered' with. Also check the injection pump for safety wired screws and check that area for chipped paint which could indicate someone was BOMBing.

Do a search on 'TST' and 'torque plate' and you'll find plenty of info on these topics. Also, if you don't have one, get yourself the Dodge service manual!

Most of the basic BOMBing mods don't change your mpg if you drive the same. However, they do allow you to drastically lower your mpg with a heavy foot!

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1995 2500 SLT Club 4x4, auto, 3. 54, 3300 pound Elkhorn slide in camper, AirLift air springs, Ricka dual wheel adapters (used only with the camper on), K&N, DC tow hooks, Rancho RS9000, Hellwig rear sway bar.
108,000 miles and counting.

 

[LandShark]

Another thing to check. Is your turbo working? Can you hear it spool up as you increase fuel? Do you get a ton of black smoke?

 

[2shus]

Originally posted by LandShark:
Another thing to check. Is your turbo working? Can you hear it spool up as you increase fuel? Do you get a ton of black smoke?

I can hear the turbo whistling good, haven't noticed any smoke at all.

 

[Skydiver]

Hello 2shus
Did you or anyone mention tire size?
Over sized (taller than stock)will give you an error on your odometer. Please list your tire size.

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96 3500 Feline deceased. Ready to upgrade. 86K. auto,3. 54,Ext. cab.
K&N air,Star wheel spun,silencer ring hanging on a nail.
Truck looks just like the truck on left side of page 6 issue 31.

 

[2shus]

I have listed my info on latest posts, i hadn't gotten around to filling it out yet. I am running 305/70-16 tires but the pinion gear has been changed and the speedo has been clocked and is right on. I'm going for a valve adjustment, i doubt if they have ever been adjusted. I am also gonna lose the cat soon. Who can tell me is it better to lose the cat or just degut it????

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1995 Dodge 2500 SLT Reg. cab 4x4 Auto,L. B. 12 valve, 3. 5 rears, 112,000 miles Anti lock brk sys, 305/70-16/Mickey Thompson Alum. wheels,Leer cap, Nerf Bars, Black/Black C/D Player Overload springs, Reese Hitch, T. C. Lockup switch, Cats in heat needs OVH (coming soon)

 

[illflem]

I think it's better to replace it with a straight pipe and leave the cat intact,you never know when you might need it and those things are pricey.

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95' 25004X4,AT,Driftwood,Banks Stinger,Warn fender flairs and running boards(work truck)
95 3500,5 speed 3:54,BD E-brake,Driftwood,Banks&Psycotty,34,000 GCVW apple and tractor hauler(works harder truck)