[riodeloso]

I'm looking to purchase a 136wb high top as a daily driver/surf van/stealth camper. I drive in California, so much of my driving is highway, some grades and high elevation expected at highway speeds. I tow only occasionally, and only to move heavy items I've purchased.

I test drove a 1500, but a regional dealer has a good deal on a 2500. I realize that the paper differences are basically suspension and gear ratio...anyone with experience with both? Suggestions? I would guess that the 1500 gets better fuel efficiency unloaded, but not enough folks are reporting economy numbers to be sure. Any input is appreciated.

 

[Dwight]

There are conflicting publications on gear ratios out there. Some documents from Ram stated all gear ratios were the same. So, I'm not sure what is true.

 

[carnut]

I'd get the 2500. With grades and high elevation the higher numerical gear ratio will help you stay in 6th gear more. Read the comments here on how easily the PM wants to shift down on even slight grades. The 1500 has the same final drive ratio as the minivans. It's not appropriate for a heavier vehicle bucking more wind. I don't believe the 1500 will get any better mileage in real world driving conditions. Around town you will also have better acceleration.

I want a low roof so 3.16 is the only thing available. If the 3.86 from the 3500 was an option I'd get it.

 

[uncubed]

What about tires? I was wondering about if the 2500 and the 1500 have the same tires,
size and rating. I have seen pictures on the web of Pm's with small tires. Could this be
possible? Or am I seeing things?

 

[30 Ounce]

There are conflicting publications on gear ratios out there. Some documents from Ram stated all gear ratios were the same. So, I'm not sure what is true.

The diesels all have the same final drive ratio. The gas version has 3 options.

What about tires? I was wondering about if the 2500 and the 1500 have the same tires,
size and rating. I have seen pictures on the web of Pm's with small tires. Could this be
possible? Or am I seeing things?

They all use the same Continental Vanco tires. I like them a lot. They have a higher load rating than most E rated tires in the US but they are really expensive. About $250 each!

 

[Adrian]

I have a 1500, 136, high roof. Bought it new March 1, 2014. I have just over 21,000 miles on the odometer. 95% highway use from Chicago south thru Tennessee mountains and Georgia area. If I make the trip with about 500lbs loaded in the van I can expect to get around 21mpg. I have gotten as high as 25mpg if I slow down and maintain 65mph without a head wind (535 miles , 21.3 gallons) on a couple occasions. The van will rarely down shift unless it's a steep hill or heavy head wind, no issue at all. The taller gear ratio is awesome for great fuel mileage. I also tow a trailer some of the time. Total weight for the 6x12 trailer is 2,500 lbs. I typically get 18.8 mpg while towing at 65mph. It can drop by 1 to 1.5mpg with headwind and at times it increases slightly but mid 18's is the norm. Towing on up hills will down shift , very reasonable if bigger uphill, but even with a lower final ratio it would down shift. I think your fuel mileage with a lower final gear, 2500 or 3500, will drop your fuel mileage by 1 or 2 mpg.

 

[Brian P]

For the 2500 owners, in 6th gear highway cruise, what's your displayed RPM at 100 km/h or 60 mph?

My 1500 has it around 1900 rpm at that speed.

I have a suspicion that they all have the same final drive ratio.

 

[Dwight]

at 70-75 I'm at ~2100 rpm on 2500. 1900 rpm is probably right for 60 mph for me too.

 

[30 Ounce]

I'm my 3500 I'm at 2300 rpm @ 75 mph. I think 60 is about 2000.

 

[Brian P]

The above few posts would suggest that they all have the same final drive ratio.

1900 rpm at 60 mph = 2375 rpm at 75 mph. Close enough ...

 

[30 Ounce]

That would be a lawsuit! They specifically detailed the final drive ratios in each model. I seriously doubt they would falsify something like that.

 

[Adrian]

Tomorrow I will drive my 1500 van and check rpm at 60mph , 70mph, 75moh and 80mph. My van has a built date in the door of September 2013, I bought it new March 1 2014. I am fairly certain at 60mph the revs are closer to 1600rpm but now reading the above post I am second guessing myself. I will confirm tomorrow.

 

[Kip-on-truckin]

All I have to add is that I ran my 3500 extended over the CAT scales a few weeks ago, and totally empty but with me in it (I'm a porker at 230) it weights 5440#. That's awfully heavy which explains the 3.86 or whatever final drive. To go from that to a 3.18:1 would require the 1500 to weigh a lot closer to 4000#, which I don't think it does. Like the rest of you, I'm turning 2000 at 60.

Regardless, it seems we are all getting right around the same mileage, 136 vs 159, low vs high as far as I can gleen from this site. Mine will just touch 22mpg if I baby it. This week I had my foot deep in it on I77 through WV and VA. I tried to keep it above 75mph for the whole run, with 500lbs in the back, and I got 17.69mpg.

One note: the uConnect average mpg and instant mpg is VERY optimistic. Hand calc'd tanks reveal that when uConnect claims a tankful averaged 21mpg, it was really more like 19.5.

I really dig the breadbox look of the 1500, but except for that I can see no reason to buy it. The high roof alone is worth the price difference as is the extra length. The **** thing turns so well there's no penalty to getting the bigger one.

 

[Adrian]

Yes I always hand calculate the mileage and have found the computer to be slighly off. I weighted mine 1500 high roof 136 at the scales empty we me in it, I am 170lbs , it weighted 5,180lbs. Only couple hundred lbs lighter than the 3500 as expected.

 

[30 Ounce]

My hand calculated mpg is usually less than 1 mpg off. Usually lower but twice it was higher. Recently went from Colorado to Florida with #1200 of tools and averaged 18.9 mpg. On the return trip we had it loaded with #4200 of pavers and tools and got 16.3.. I was averaging 17.5 until we got to Kansas and the wind was terrible.

 

[Adrian]

1500 promaster - at
60mph engine is at about 1,750 rpm.
70mph engine is at about 2050 rpm

 

[carnut]

...My 1500 has it around 1900 rpm at that speed.

I have a suspicion that they all have the same final drive ratio.

I'm afraid you may be right. The published information must have been preliminary or has been changed. According to Continental web site, the revs per mile for the Vancos should be 709. rpm @ 60 mph is simply the tire revs per mile * gear ratio (.65 for 6th) * final drive. By the numbers the results should be:
ratio rpm @ 60mph
3.16 1456
3.43 1581
3.86 1779

Analog tach is probably not that precise, but you should be able to discern a difference between 1450 and 1780 rpm. The calculated rpm with a 3.86 final drive jives with what Adrian reports. That's not so bad then - 1450 @ 60 is way out of the torque band.

It's been nearly a year since I test drove a Promaster and I can't even remember which model it was. I didn't get to drive it on the freeway or up hills. I tested a Caravan more extensively on routes I drive every day. It had to shift down 2 gears to climb the hills. I couldn't imagine applying the same gearing to a larger, heavier vehicle.

If in fact they all have 3.86 final drive, that would take away one of my objections. Lots of leftover 2014s will hopefully help with the other big objection, price.

 

[uncubed]

Took a vacation trip through the rocky mountains in western Canada.
Climbed some steep parts ,shifts down to 5 , no big deal, on the really steep parts
shifts down to 4th,no big deal. Lots of power to pass if I wanted to, but took my
time and stayed at speed limit (90kph) Mileage was 21 to 22 U.S. at that speed.
110km per hour (70mph) is about 2000 rpm's.
Mountain parks are post 90km per hour.

 

[Chris]

One way to get around the difficultly in reading the tachometer with precision and to add some data points to the investigation would be to run the van at a constant 60MPH in each of the top three gears. Using data I found on the ALLPAR article about the ProMaster and 709 tire revolutions per mile, I made a chart of the theoretical RPM's for each of the listed gear-ratio and axle-ratio combinations.

GEAR#/ratio/axle/[email protected]

6 / 0.65 / 3.16 / 1456
5 / 0.95 / 3.16 / 2128
4 / 1.37 / 3.16 / 3069
6 / 0.65 / 3.43 / 1581
5 / 0.95 / 3.43 / 2310
4 / 1.37 / 3.43 / 3332
6 / 0.65 / 3.86 / 1779
5 / 0.95 / 3.86 / 2600
4 / 1.37 / 3.86 / 3749


So, if owners of the different models are willing to participate in this experiment and report their results, that would aid this discussion as to whether there really are different axle/gear ratios.

 

[Dwight]

6 / 0.65 / 3.86 / 1779

What I saw this morning at 60 mph.