Another Hopeless Case. Ram Van 3500.

[mwilliamshs]

Originally Posted by Fat Charlie

...Changing the torque characteristics before you've got control over how the power output gets used is putting the cart before the horse- literally.

Nope, still figuratively. Literally would involve a horse and a cart

[Fat Charlie]

Originally Posted by t vago

Or save for a manual conversion, instead.

I had a manual Xterra. Trying to hypermile it was a waste of a good manual transmission. An auto may have been worse, but not by much.

[96CX]

Originally Posted by Fat Charlie

Get me the VIN. There's a lot of information in there.

Sorry I've been AWOL. Been working and working on remodeling the house...Yay, projects! Blah.

Anyway, here's the VIN, for what it's worth: 2B5VB35ZX2K119553.

[Fat Charlie]

No good. Maybe with 2B5WB...?

Some fun codes:
Build date: 1/29/02
A07 5.9L Engine(EML)/4Sp Auto Trans(DGT)
ADP Heavy Duty Suspension Group
BAZ Alternator - 136 Amp
BGK Brakes - 4-Wheel Anti-Lock
BKJ Brakes - 12x3.5 Rear Drum
DGT Transmission - 4-Spd. Automatic,46RE
DHA Torque Converter - Lock-Up
DJE Front Axle
DMF Axle Ratio - 4.10
DRC Dana M60/248MM Rear Axle
DSA Axle - Anti-Spin Differential
EML Engine - "Magnum" 5.9L SMPI V8
HAA Air Conditioning
HBB Air Conditioning - Rear w/Heater
NAA Emissions - Federal
NBK EVAP Control System
NFT 35 Gallon Fuel Tank
NHB Cooler - Auxiliary Transmission Oil
NHM Speed Control
NMC Engine Cooling - Heavy Duty
SFB Shock Absorbers - Front Heavy Duty
SGB Shock Absorbers - Rear Heavy Duty
SHA Stabilizer Bar - Front
SUA Steering Column - Tilt
TYT LT245/75R16E BSW ALL SEASON TIRES
Z3E GVW Rating - 8700#

[t vago]

The 5.9L V8 is a very thirsty engine. Its JTEC engine computer doesn't help much, in that regard, either. They tend to do excessive WOT enrichment if the throttle is depressed more than 1/3 open. Maybe there's some easy way of advancing ignition timing on it? Might also consider some sort of clamp circuit on the throttle position sensor, to make it not do WOT enrichment.

[96CX]

Originally Posted by Fat Charlie

No good. Maybe with 2B5WB...?

That may be it. I had it scribbled on my hand, so it could have been a U or W easily enough.

[ALS]

One option you will not like, drive slow, like 55-60 mph and the other is to raise the rear gearing to 3.73's from the 4.10's. I wouldn't go any higher due to weight of the vehicle.

Another option as was suggested before is a good air-dam and if you have the time and money a full belly pan under the vehicle.

The largest problem you have is the size of the van. There is no easy or cheap way to drop the Cd and or weight on that beast.

[Reed]

I am a very long time lurker and haven't posted much at all. However, I am also a big fan of full size vans and Dodge vans and vehicles. The four speed Dodge 46RE is a fine four speed automatic transmision that has a lcokup torque converter and overdrive. It is based on the old very reliable and sturdy A904/A727 design so you really don't have too much to worry about in terms of longevity. Making sure the bands are properly adjusted and good fluid is used is about all you need to do. Use the latest Dexron version, VI I think.

With 4.10 gears you will definitely need to use the overdrive on the highway.

The 360 Magnum is about the best of the old pushrod engine technology that Chrysler did. You won't find much in the way of efficiency improvements in that motor.

As has been mentioned above, the engine is already fairly efficient. Simple things like running syinthetic oil (5W-30, or lighter, maybe 0W-30 or 15 or even 10 if your pressure is good enough) to reduce internal drag, making sure your air filters are clean, making sure you have the correct temperature thermostat, etc...

Old full size vans are "dirty" from an aerodynamic perspective, but as has already been mentioned modifications like an air dam are actually more harmful than helpful in everyday driving. A bellypan might help, and some kind of a kamm-back modification, but really something simple like the standard luggage rack put on conversion vans might be enough to break up the airflow off the back of the van and reduce drag.

Your best options are to drive conservatively, reduce the weight of the van, and reduce parasitic losses from fat tires or too-thick oils. The only modification I would do to improve economy would be to increase the rear axle gear ratio to something like 3.9 or 3.5. However, you are driving a big heavy brick and the lower 4.10 gear ratio will actually help the fuel economy in town in stop and go driving.

I once had a 1984 Ford E150 full size conversion van equipped with a 351 high output engine (four barrel carb) and a C6 three speed transmission and a 3.5 rear axle ratio that I tuned to the point where I could get over 20 MPG highway if I drove conservatively. But where is the fun in that? I typically drove 75-80 on the highway and got mid teens in fuel economy. But the engine ran so lean that I melted the top oil control rings on all the pistons and had to get the engine rebuilt. That drivetrain powers my current 1989 Ford E150 that I converted to MAF based sequential fuel injection. It still gets about 13 MPG on the highway no matter how fast I drive, but runs smoother than ever.

My brother has a 1983 Dodge full size short wheelbase van that has a 225 slant six and A904 three speed auto trans that I have tuned to get about 15-17 on the highway consistently, even driving 60+ MPH.

Vans are built for comfort and work, not for max fuel economy. With a full size American gas powered van getting anything above 12 on the highway is a good accomplishment. Aero mods really won't help much unless you do LOTS of highway driving.

[Frank]

We have a 2000 Xplorer camper (based on the 3500 Ram Van) with the same mechanicals and typically get 9-10 mpg pulling an enclosed motorcycle trailer. I don't know what it'll do w/o the trailer but 12 would seem possible. The Xplorer has a 42" extension welded on, awning stuck out into the wind, large "trailer" mirrors and some weird-ass television antenna platform mounted on the roof. I typically drive 55-60 on the highway (O/D off) when towing and as much as I'd like, I don't expect much better mileage ever. The issue with these big vans is simply lousy aero and a lot of weight. I changed rear differential fluid to full-synthetic and didn't notice any change in mileage at all.

I do try to minimize weight by not completely filling the water tank, etc. but it is what it is and it's hard to expect better. I plan to remove the antenna platform but it's pretty hard to work on the roof and I worry about water leaks. The best solution is just slow down as much as you can get away with. It's a great tow vehicle and I use the built-in generator to charge my bike at the dragstrip (electric race bike.)

[t vago]

Not sure when the 46RE torque converter is told to lock up, but...

On my Dodge Dakota, torque converter lockup normally occurs at 45 MPH. However, in OD OFF, lockup occurs at 35 MPH. Yes, it's a 545RFE, which is a different animal, but you might want to look into when lockup occurs for the 46RE in normal and in OD OFF.