This has been an on going experience for the past two years of what works what does not.

For the longest time, the Ram Van B2500 12-passenger, V8 5.2L/318cid Magnum, 36-gallon tank, with the 46RE, 3.92 rear, and the heavy weighted frame + 8-lug wheeled suspension has not managed to hit above 14mpg in a very long time. I just thought it was high mileage. After doing some digging (reading and experimenting) of what these ultra marathon mileager's are doing, I set out to try a few reasonable things.

We had just finished a family trip from Nashville to FL; 10 of us all packed in with the goods. From fill up to refill a few times, we averaged 18.59mpg. On the tank full that did not have the mountains, rush hour traffic, no construction, no sitting on the interstate due to accidents, the van did an amazing 19.7mpg humming along at 65mph. To see the mileage OD turn past 400 and it was just above a 1/4 tank was shocking. Usually, 340-360 miles per tank was the best this van could do.

Here's a few of the things that helped.

* Brakes
- Tune in those rear self adjusters from keeping the drum brakes from dragging.
- If the brake hoses are over 10 years or the van has sat for a very long time, replace them.
- Find a very low friction and high temp bearing grease and repack the front inner and outer bearings.
My van is using a blue lithium bearing grease from the Tractor Supply store TSC. <---DO NOT DO THIS. I just repacked again with a Molybdenum Lithium grease today!!!<--- DO THIS.
Brand: Valvoline SYN-Power P/N: VV986, It's fully synthetic, moly-fortified, temp range -40F to 400F, Meets NLGI #2 GC-Lithium complex EP grease. Exceeds all domestic vehicle applications.
- Bleed the lines very well.
- Clean the front pad guides on the calipers or ensure that the metal guide clips are not binding the pads from moving.

* Exhaust
- Recently, my CAT and muffler went bad last Fall. I had opted for a high flow CAT, high flow exhaust. Plus where the two pipes come together before the CAT, the OEM has them pinched somewhat restricting good flow. Oh, after the CAT run with 2-3/4 or 3-inch exhaust pipe.

* Tires / suspension
- Chrysler has a TSB mentioning that the load-E tires for handling, safety and mpg are ideal for the Magnum series vans that have the 8-lug wheels. The previous Yokohama tires were not ideal for my van; they wore faster, to soft on the road, traction degraded within 6 months. The BFGoodrich Commercial T/A's load range E are still doing well, traction is holding, tread wear has not even been noticed.
- Alignment is really needed too. Don't go shops with the old school alignment methods. The newer last alignments are dead on.
- Have the suspension looked over for anything that may be failing. (control arms, etc ...)

* Rear Axle
- Chrysler has a TSB out for using 75W90 now in the rears vs. the 80W90. This helps with fuel mpg. While in Georgia, we had visited Summit Racing at exit 216 on I-75. I had picked up a second bottle of Red Line 75W90 synthetic.

* TB
- Other than doing the entire TB replacement with a Fastman TB ( http://www.thefastman.com/Throttlebodies5x.asp ), I've taken the DIY approach and ground down the TB two barrels on the MAP sensor side and didn't touch the IAC side. If you do the TB barrels all around, expect loud rushing noises while at idle and possibly idle issues. Otherwise, this will improve the mpg, Hp, and throttle response. This photo shows all sides ground and smoothed down.


* Engine
- Plugs are the Autolite AP5224 (single Platinum) side gaped like racing plugs. There are at least three threads here in the B-van section talking about this topic. No sense doing that all over again.
- New 7mm or 8mm wires following the TSB for the ignition wire layouts. (critical)
- Cap and Rotor must be of the copper/brass type period. NEVER use the cheap aluminum metal material.
- Cap needs a vent plug. Reduces moisture issues.
- Running with the Purolator L30001 filter for added capacity.
- Using Castrol 5W30 and 10W30 mix non-synthetic at the present.
- Goodyear Gatorback belt. For my 2001 magnum 5.2L engine with AC, the p/n is 4071005 pack number is 7PK2555.

* Tranny
- ATF+4 only.

* Cooling system
- Replace nearly everything early this year except for the heater cores of the front and rear HVAC systems. All hoses, water-pump, fan viscous clutch, T-stat, radiator, and S-belt.
- A T-stat at 195 helps with fuel MPG. Sure, the 180 t-stats help with performance, but the fuel savings won over the small performance gains. Use a Super Stant for long lasting life. The regular Stants are worthless.

That 19.7mpg still blows my mind thinking about it.

Only two things left to push this van to 20+mpg. Summit Racing has electric eFans for electric cooling the RAD.

David's van had hit the 20mpg mark over a summer ago. It was difficult to believe. He had listed a few things that got his van there. With the steps taken on my van, it seems very realistic.

Of course not all of the items listed were towards MPG gains. Parts failed and needed replacement in the two years. Just glean what you can to help your MPG improvements.

 

i really like this write up, BUT i have a 2500 van, with a v6! it has the 3.9l, with a 3.5 rear axle ration, and a 3 speed auto tranny (not sure if it has od?)

is there anything like this specifically tailored for me?

 

All that Stev wrote will help the V-6 3.9L as well, though you may not see as much of an improvement you will see some gain in mileage. Now on the tires his are for the 1ton with 16 inch rims. On the 15 inch rims we should be using LT (LT235/75R15) or XL (P235/75R15XL) rated tires that can handle up to at least 50 psi (some have tires that handle up to 80 psi. Adding more air to those type of tires that can handle it will help with mpg. A couple of members on this forum are running about 50 psi in their tires with great success.

Your van uses the 3 speed only transmission, it does not have OD.

 

The 3.9L Magnum is engine is basically the 5.2L engine with the rear two cylinders chopped off.

You can change out the rear axle fluid to the synthetic 75W90 and lube (repack) the wheel bearings. Also the TB mod will hep some.

I had a Ram Van B1500 with the 3.9L. The van ran great when I had it. It was sure a bummer knowing that the tranny lacked OD.

Tires that are the highest load and the least side wall bulge will offer the best mileage too. 15-inch tires for the 1/2-ton and 3/4-ton frames with higher load ratings are getting harder to find these days.


It would be very nice to hear other mods or improvements from others to increase the MPG. Much of my research is literally hours of reading Ram Truck and Ram Van forums and the Dodge/Plymouth forums that used the 3.9L/5.2L/5.9L Magnum engines.

 

are there specific ram van forums? i found this site mainly for our old urango and dakota... my in-laws are a huge dodge family. their new addition is an 05 durango, thus the reason i got the van

 

Yes, there are a few Ram Van forums out there. Of course, if I post them here or PM, this site blocks the address. Just do a goolge search of ..... "Ram Van" forum ..... Keep the Ram Van in quotes. Or also do a search of "Ram Van" with "Alloro". This will turn up a few more as well. Many of us regulars are here and on the three others.

 

You make me sound like an internet rash!

 

So do you know what gave you the best fuel improvement?

was looking at what you say about Tire Pressure, I have the BF Goodrich on the Van 235/75/15 however it says on the side wall Max 35 PSI and I have around 40 in there at the moment. They handle good on the van and very little loss on treadwear, infact the depth check they do with my oil change added 0.1 to the depth.

The only other thing I see is the exhaust but won't be touching that. I get just under 17 MPG guess that could be the difference of not having O/D.

 

Keep at the top end of what the tire is rated for. My tires are LT225/75R16 Load-E. The higher load has an inflation limit of 80psi max. Your tires max out at 35psi. You would need to upgrade to a new set of tires to have the benefit.

Friction reduces MPG. Look at the components that tend to have the highest friction. Wheels, bearings, belts/pulleys, brake drag, oil lubricants (differential/power steering/tranny/engine oil), ...

Then look for better air intake to better exhaust outlet.

Running the 180 to 195 T-stat helps keep the emissions lower and improves MPG.

 

Just an easy bump of this thread since fuel prices are going UP UP UP !







.