[OregonPlumber]

Nice to have found this Forum.

Just picked up a 2500 high roof last week. So far I like it alot but the manual that comes with it says nothing about shifting the transmission.

Can someone please explain the best way to shift in order to maximize gas mileage?

In town I suppose you just leave it in Drive.

Also on the highway where it's flat I would guess Drive is the way to go.

I drive about a 3 mile curvy uphill stretch of road every day at an average speed of about 20-25 mph. Then it's about 5 miles of straight highway going downhill. Should I be shifting to the + and - going up or down?

 

[bobojay]

Not owning a ProMaster, but owning a Jeep Wrangler with the same motor, I can give you an idea of what has helped me.
First of all, I'd run it in tow/haul all the time. It will keep the engine up closer to it's more efficient rpm levels.
Second, what I do, since the Jeep doesn't have the tow/haul mode, is if I know I'm just going to be tooling around town, at say < 45 mph, I leave the trans in 3. You'd probably want to use 4 with that 6 speed and a lower final drive than I have. Any faster cruising, I use 4. Outright highway driving, I leave it in 5.
This has consistently gotten us 18 to 21 mpg tracked over 20k + miles in this Jeep, which is higher than the EPA rates it.
Incidentally, running your trans in tow/haul all the time will not harm anything. It just changes the shifting algorhythm a bit....

 

[Ram3500']

i don't own a PM yet, but in most of my vehicles, the strategy I used to find the ideal RPM is to drive normally, keeping up with the flow of traffic and doing that while trying to use the least amount of effort from the engine. Doing that for a bit you'll find the RPM

 

[OregonPlumber]

Thanks for your responses.

Perhaps I am just a dumb plumber, but I'm still not sure about how to drive this thing. So if I leave it in tow/haul mode what is an ideal rpm when climbing a hill with the van about 1/2 loaded? How about when I am coasting downhill in a long stretch of highway?

Is there a website where i can read more about the best way to shift this thing?

 

[Chance]

.....cut.......

I drive about a 3 mile curvy uphill stretch of road every day at an average speed of about 20-25 mph. Then it's about 5 miles of straight highway going downhill. Should I be shifting to the + and - going up or down?

Just my opinion, but I'd drive it like any other vehicle.

Uphill is easier. Depends on how fast you want to go and how much gas you are willing to spend to go that fast. Keep engine at or below 3500 RPM or so and you'll save most of the fuel you're going to save anyway. If you are in a hurry and step on it and climb at much higher revs, like 5000 to 6000 RPM, then getting to the top of your hill will cost you more fuel.

Going downhill is more important because it involves safety. Downhill fuel consumption is negligible and I wouldn't take it into account. The slower you want to go downhill the lower the gear the transmission needs to be in to provide added engine braking. On switchbacks I don't mind tapping the brakes occasionally to reduce speed, but I avoid riding the brakes when possible. If the van gets going too fast just shift down to hold a slower speed.

I don't have a PM yet so I don't know how the transmission is shifted manually. On Ford vans and RVs I've driven, when going downhill with transmission in TowHaul, the driver can force a downshift by momentarily tapping the brakes. Or you can manually use the shift lever to select a lower gear.

The ProMaster is probably different than a Ford, but the owner's manual should cover details of how to operate it properly.

 

[alarmguy]

From the OM:

"When operating in TOW/HAUL
mode, transmission upshifts are delayed, and the transmission
will automatically downshift (for engine braking)
during steady braking maneuvers."

 

[OregonPlumber]

Thanks for all the great replies. My PM is sitting in my driveway until I can get a mat on the floor and bins in the back. Have only driven it a few miles so far. Looking forward to using it every day.