Engine/Transmission (1994 - 1998) Average 3500 4x4 5spd mpg?

[Coalsmoke]

Hey guys, what are the 12V 3500 4x4 5spd extended cab trucks getting for mileage? I used to have a 1995 2500 4x4 reg cab, and it was great. I remember one summer doing all highway driving I hit 23MPG with a load in the bed. My father has a 97 2500 4x4 extended cab 5spd, and only gets 16-18mpg, but he drives it like a car and I think he maybe has a fueling issue.



I'm getting tired of the payments on the new truck and am looking to go back to the 12Vers. I would like to pull a 14K gooseneck flatdeck, so I am looking at a dually, even though I'd prefer a 2500 single rear wheel. I just don't want to take too big of a hit on the mileage if I do go the dually route. 6 tires will be bad enough

 

[DonTX]

I have no idea what the 4x4 does to mileage, but I think gear ratio plays an important part of the issue. My 2wd automatic will get 23 empty on the highway easily. The dually don't seem to actually cost mileage in my opinion, don't forget each tire has lighter loading.

I far prefer the 12v models, I could have most any truck I wanted, and I have exactly the one I want. It is a keeper! You can see it in the gallery.

 

[Coalsmoke]

Hi Don, thank you for the input. I think you are right, the gear ratio is very important. You have a very sharp looking truck!

 

[RHestand]

If I had a choice, I would rather have a 3. 54 gear rather than the 4. 10s I now have in my 98 12V auto. (Anybody want to trade?)

My empty mileage around town and on the road, (at no more than 65mph) is a little over 17, and almost 20, with cab ht. camper shell.

Ray

 

[AndrewKing]

HI All,

I have a 1997 4x4 ext cab dually (basically stock as far as I know). 5 sp, Straight through stock exhaust (previous owner deleted the muffler and the exhaust ends just before the rear diff)... . 4. 10 gears and it has a Leonard cab height cap on back... . I got a best of 16. 8 MPG so far (driven at a sedate 62 MPH... I tried to keep engine RPMs below 2250 because I hear the extra revs will kill mileage).

On several trips hauling an empty 7x16 V nosed enclosed trailer (tandem axle... . approx 2260 lbs empty weight) and returning without the trailer (I delivered the trailers for sale to). I average about 14. 4 mpg... . (trip speed about 62 MPH... only a little city driving)

I know higher rear end gearing would get me better mileage but costs too much to switch out the gears and US gear is out of business (sniff sniff!)... . I didn't want to go the Gear Vendor route... .

Anyways, Hope this helps you.

Andrew

 

[Coalsmoke]

That 16. 8 would have me looking for ways to improve it. With my 95 I had 33" tires, 3. 54 gears, and would rarely be at above 2000 RPM.

 

[Jorge]

That 16. 8 would have me looking for ways to improve it. With my 95 I had 33" tires, 3. 54 gears, and would rarely be at above 2000 RPM.

I have a 1996 DRW Ext cab with an auto and 3. 54's. I changed the 215 tires for 235's. I used to get 22 to 23 mpg with stock exhaust. I read all of the TDR's readers advice to remove the cat and the muffler. What a mistake. I lost about 4 to 5 mpg. I think it has to do with back pressure and some heat. I have since reinstalled the muffler and my mpg is coming back. I recently pulled my 35' travel trailer to Kentucky and back. 12 to 13 with 30 to 35 mile head wind. 17 to 18 with no wind, tach at 1800 trailer weight at 9000 lbs. With 250K on the clock and the original transmission still in place, I should not cry. I wish someone would call me and want to trade my transmission for a 5 or 6 spd. ( The ultimate in wishfull thinking) I also think diesel fuel has changed. It no longer has the lubricity that it once possessed.

 

[DonTX]

Wow, has anyone else found lower mileage with the cat and muffler lost? I would not have suspected that to happen.

I have a 1996 DRW Ext cab with an auto and 3. 54's. I changed the 215 tires for 235's. I used to get 22 to 23 mpg with stock exhaust. I read all of the TDR's readers advice to remove the cat and the muffler. What a mistake. I lost about 4 to 5 mpg. I think it has to do with back pressure and some heat. I have since reinstalled the muffler and my mpg is coming back. I recently pulled my 35' travel trailer to Kentucky and back. 12 to 13 with 30 to 35 mile head wind. 17 to 18 with no wind, tach at 1800 trailer weight at 9000 lbs. With 250K on the clock and the original transmission still in place, I should not cry. I wish someone would call me and want to trade my transmission for a 5 or 6 spd. ( The ultimate in wishfull thinking) I also think diesel fuel has changed. It no longer has the lubricity that it once possessed.

 

[Coalsmoke]

That is very interesting about the cat. I remember that I found on my 95 2500 I gained approximately 1mpg with the removal of the cat and exhaust improvements. It would not surprise me though to see two slightly different trucks react differently to the same modification. Other factors matter too, like whether the exhaust pipe was upgraded in diameter or left at the stock 2. 75" (or whatever the exact stock size is). I had upgraded to 4", and later added a big rig muffler to cut down on the cab noise and noticed no change in mpg. It seemed to me that the turbo also spooled up faster as well after the cat was gone and the exhaust was upgraded.



I'm going to be looking at a 96 2500 today. I was originally set out to find a dually, but I think I found a way to safely occasionally haul a 14k gooseneck with the lighter truck by spreading the rear trailer axles apart a couple more feet and only putting about 15% of the trailer weight on the truck. The added traction of a SRW vs a dually is pretty important to me as well, being in snow and mud country.



I agree about the change in diesel fuel with the introduction of ULSD. I use Redline fuel lubricator at every fill-up. In this new 2008, with these fancy injectors working 3 times more often and costing 500 each, I can't afford to loose one, let alone 2 or 3

 

[Jorge]

I know there is a fine line somewhere in the exhaust system where unloading the restriction will help the turbo spool up faster, however with the original version of "stock" except the exhaust system, I only have the mpg to judge by. The hotter the day the better it is on mpg. I remember pulling a 10K trailer through the South and up the east coast and traveling 3600-3700 miles and burning 204 gallons for the trip. Geno's garage used to sell blankets that you could put around the exhaust manifold to increase efficiency and the principal was to keep heat in the exhaust. Still baffled but not crying

 

[DonTX]

Wow, I will be coming to Blue Springs MO in a week or two - empty. Got anything you need hauled up there?

I know there is a fine line somewhere in the exhaust system where unloading the restriction will help the turbo spool up faster, however with the original version of "stock" except the exhaust system, I only have the mpg to judge by. The hotter the day the better it is on mpg. I remember pulling a 10K trailer through the South and up the east coast and traveling 3600-3700 miles and burning 204 gallons for the trip. Geno's garage used to sell blankets that you could put around the exhaust manifold to increase efficiency and the principal was to keep heat in the exhaust. Still baffled but not crying

 

[Dave M]

I have a 97 3500 dually Club Cab 4x4 5spd with 4 inch MBRP straight thru exhaust and AFE open air filter. I get 15-18 MPG. I'd like to get 20+ MPG, so how do I do it?



I want to change timing to 16, 3K Gov springs and #10 fuel plate, all setting in tool box but I need timing tools first. How will those mods affect mileage?



Thanks,

Dave



Edit: I have stock 3. 54 gears

 

[AndrewKing]

HI,

I don't know about 20+ in what we have (altho I have heard a bunch of first gens can do that) but I think gearing has the most effect on mileage... . I know my 4. 10s are hurting me BUT man can that thing pull!

I would really like better mileage but regearing and/or another overdrive would be a bit expensive...

I wonder about meth injection and those hydrogen generators.....

Andrew