Another Hopeless Case. Ram Van 3500.

[rmay635703]

Originally Posted by 96CX

We bought a van. '02 Ram Van 3500 extended. Basically the biggest van we could find. And it gets 12 miles to the gallon. We're planning on using it for road trips and such, so any degree closer to 20mpg will be fantastic.

Dodges of that era tend to have leaky intakes (aka random vacuum leaks)

If you take the time to identify and fix all the leaks and the seals also tend to leak, your experience will improve by about 50%

And dodge autos are the absolute worst thing ever, a manual transmission DOES make a huge difference just because dodge made crappy autos in the early 2000's.

Good Luck
Ryan

[ksa8907]

Originally Posted by 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.

Do not use anything but atf+4 fluid in a chrysler transmission. The reason chrysler transmissions have a bad rep is uninformed shops and other people doing maintenance thought, and would preach, that dexron with an additive was the same as atf+4. IT'S NOT!!!!!!!

[Frank]

IIRC there was a known problem with converter lockup and consequent "shudder" as it can happen at too low a RPM. 4th gear is a pretty high overdrive so even with the 4.10 rear gears it's easy to really load up the engine.

I had a no-start issue which was (I hope and pray) permanently resolved when I changed plug wires at the end of the year. (Bad coil wire, going open intermittently, but I haven't driven the vehicle enough since then to know for sure.) I'm hoping there was some sort of non-obvious misfire that was hurting economy but I'm not holding my breath.

[Reed]

Originally Posted by rmay635703

And dodge autos are the absolute worst thing ever

Care to cite a source for this misinformation? The 904 and 727 family of three speed automatic transmissions are widely recognized as one of the most durable and simple transmissions ever made. The A500/A518 or 4?RH or E (however you want to designate them) are esentially 904s and 727s with an overdrive unit scabbed onto the back. The front wheel drive four speed autos had a bad reputation because ignorant owners and techs didn't use the proper trans fluid for them. At the time they were introduced through recently, ATF+4 was the only transmission fluid that should be used. I prefer Dexron VI because it has the performance specs that exceed those of ATF+4 in the impotant aspects (lubrication, friction, etc...). Plus it is cheaper than ATF+4. I never put any additives in engine oil or transmission fluid and I don't recommend anyone else does, either.

The TC lockup shudder was a problem in 1979-1980 when the lockup TCs were first introduced. Chrysler released a fix which was a stiffer spring that went into the valve body that raised the loclkup point. This problem was solved by the mid 80s. Later transmission problems are mostly due to ignorant users putting in the wrong fluid.

But don't take my word for it. Do the homework and learn about it yourself:

allpar.com/mopar/torqueflite.html

allpar.com/mopar/four-speed-automatics.html

If I remember correctly, overdirve on the A500/A518 is somewhere in the neighborhood of a .3:1 ratio. This would put you in the 2500-3000 RPM range cruising on the highway with 4.1 rear gears.

Again, in a full size van with a V-8 engine, anything over 12-13 MPG is a good day. Your best bets for inmproving economy are reducing weight, driving conservatively (install a vacuum gauge and drive to maximize vacuum), and reducing internal engine and transmission inefficiencies (run lightweight synthetic oil in the engine, make sure the trnas is adjusted properly). Low rolling resistance tires might make some differnce, but they haven't done anything noticeable on my 89 Ford full size van. Just drive your van and enjoy it. Just remember that you can't put a bed in the back of a prius or haul very much in the back of a leaf.

[Ptero]

My experience is LLR tires with max rated pressure give the biggest gains.
Oversize diameter rear tires will help with a 4:10. Lock-up occurs 2-3 mph (actual) higher.
Narrower tires will help.
Slow acceleration. Speed = just above lock-up (lock-up occurs about 45mph).
The return on aero mods diminishes with the weight and size of the vehicle (save it for your car).
Make sure your torque converter clutches aren't slipping. This disables the lock-up and throws error code P1740 TCC.
I use the dangerous practice of checking for vacuum leaks by spraying a little starting fluid around the intake manifold. If revs go up you have a problem.
This is a reliable engine but will suck gas. Not much you can do.

What you can do is have a beer. Now, take the number of people you are traveling with and multiply your mpg by that number. That is your passenger miles per gallon, which is a real number.
Have another beer. Figure out the weight of all the stuff you are hauling around and divide that by 160. Add that to the number of passengers and multiply your mpg by the result. That is your passengers and stuff miles per gallon which is not quite a real number but close.
Have another beer. Take your GVW and divide by 2. This is a sensible weight for a van using composite materials, designed in an imaginary world by BMW. Call the other half your stuff (you like hauling a couple extra tons of steel every where you go). Divide that number by 160 and add it to the other numbers, then multiply by your miles per gallon. That is your Hey I'm a steel hauler with passengers and stuff miles per gallon which is not a real number at all but all your friends with vans will think so.
Have another beer. Read the newspaper. See that article on the price of gas? Laugh. Laugh your head off.

[Reed]

Running max sidewall pressure on tires on a truck or van or vehicle used to haul heavy loads is asking or a blowout due to overheating of the tire. Been there, done that. The max inflation trick works for lightweight passenger cars than don't carry much of a load but is dangerous on working vehicles. When you are operating a load carrying vehicle you really do need to follow the manufacturer's recommendations for tire pressure. And if you have a truck or van you should also run light truck tires, not passenger car tires.

I figure that getting 13 MPG highway in a full size van carrying 3+ passengers and their luggage for a weekend trip and travelling at 70-80 MPH is pretty decent efficiency.

[oil pan 4]

Agreed, do not run P-metric tires on a full size truck or van.
If you do run P-metric tires on a full size vehicle all the tire manufactures seem to agree that you should de-rate the tires load capacity by 11%.

[Ptero]

Running max sidewall pressure on tires on a truck or van or vehicle used to haul heavy loads is asking or a blowout due to overheating of the tire.

I said max rated pressure. That's within spec.

And if you have a truck or van you should also run light truck tires, not passenger car tires.

Who's talking about passenger car tires?
DEFENDER LTX M/S LLR Michelins are made for this van.

Been there, done that.

Yeah? I got over 2 million miles on heavy trucks, bub. You need to practice reading a little more carefully.

[rmay635703]

Originally Posted by Reed

Care to cite a source for this misinformation?

Instead of arguing with me I have a low mile truck for sale, pick it up and buy it, tired of nickle and dime...


Hmm, lets see, my 2001 Dodge Ram Crewcab 1500 V8 2wd auto is effectively a clone of his van.

I know someone else who owns my same truck but in stripper mode with a manual transmission, 2wd, etc.

His truck has always gotten around 20mpg even around town, my truck driving like grandma 40-50mph could never beat 18mpg in the summer on longer trips without extremely impractical hypermiling tricks and even then I usually only gained a mpg. In the city on shorter trips I was lucky to break 12mpg, while his stayed about the same. His truck has around 180,000 miles, mine now has 80,000.


Add to this

I had to have my transmission partially rebuilt at 40,000 miles, only $650 but still irritating (aka the repair place was amazed my tranny wasn't junk because it would stay in whatever gear was selected, so if it was in OD, it stayed that way all the time even at a stop sign, me being the intelligent person I am recognized this and shifted it like it was a manual until I could have it repaired. Most owners apparently just stomp on it cause it doesn't go and take out the xmsn.

I have never owned a vehicle that had to have the transmission touched at 40000 miles, that even includes the terrible 700r4 GM put behind its diesels in the 80's.

Add to this Dodges transmissions of that era are one of the least efficient 4 speeds on the market, the real need for cooling on dodge transmissions is a good sign that the heat is being made from something, and that something is inefficiency.

And Saying that the 3speed dodge transmissions are ANYTHING like the 4speed is a joke. The 4th gear is so weak you cant tow in it and you have to be carefull. If you know this and the fact that the electronics fail you can work around it but still, my Dodge ownership has been one of the worst experiences, I have to constantly replace a blasted $50 metal gasket because the damn thing leaks, I keep having seals go, the front end sticks and will need some sort of replacement at 75k. The interior is deteriorating and falling apart, I won't have a dash soon.

I can go on, never had any of this crap before.

Total Garbage.

[smcguyer]

That is the approach I would use, assuming you have shed as much weight as possible and cannot change the axle.

The simple vacuum guage tells you if you are making changes in the right direction. If you make a change to the vehicle/engine and you see a higher vacuum reading for the same speed, you will most likely be able to get better mileage. Because the throttle plate is closed more thus less air/fuel mass is being consumed for the cruise condition.

Find articles on optimizing cruise fuel economy for that engine. The basics are reducing flow restrictions in the intake and exhaust system (i.e reducing pumping losses). Then increase the charge density of the fuel/air mixture at cruise (i.e. colder air mass allows for less throttle plate opening). Then try to tune/control the engine management to enable lean burn, with increased timing advance... at cruise.

This means you have to override the limitations of the oxygen sensor /cat converter. Some engines respond well to lean burn with advanced timing (at cruise). You push it as far as you can as long as the vacuum guage keeps reading higher vacuum, and you just avoid lean burn detonation. The less your throttle plates are opened at cruise, the better the results you will probably see with this approach.

A Scanguage or other type of electronic guage might tell you the amount of throttle plate opening you have to begin with, and also the vacuum.

On older heavy vehicles with a carburetor, you drove while watching the vacuum guage. This is because you wanted to drive with a high enough vacuum to prevent the carburetor power valve from opening. If the vacuum got below, say 6", the power valve would open and richen the fuel mixture and you got less economy. So you would drive the vehicle in a way to try to realize the highest vacuum guage reading.

You have to find someone who has actually done economy tuning on that engine, to know the results without trying it yourself. Call the engine tuners for that engine and see if any of them have done it (for cruise conditions)....although most changes made to an engine to develop more power also translate to better fuel economy, for all the physics reasons mentioned above. David Vizard is a tuner that has experimented with lean burn alot, starting with carburated engines. But all the principles apply to fuel injected engines.