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... data I found on the ALLPAR article ...
That site also claims a 4th prime (1.57) which may complicate interpretation.

The “fourth prime” gear carries on the tradition 45RFE/545RFE’s “prime” gears, used for kickdowns only. When the driver accelerates, the transmission uses the standard fourth gear; when the driver hits the gas from fifth or sixth, the transmission may kick down to “fourth prime” instead, to make the shift feel smoother.
It might be hard to tell which gear you are in after downshifting . No conditions are specified for shifting to 4th prime or 5th. It would be nice if the display would show what gear you are in.
 

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The differences will be easier to see at higher speeds. Mine is 3500. At 60 it looks like I'm at 1750. At 75 I'm at about 2350. At 70 its about 2200. Definitely different than what Adrian posted for his 1500 except at 60...
 

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... At 60 it looks like I'm at 1750. At 75 I'm at about 2350...
That just doesn't make sense.
75 / 60 = 1.25
1.25 * 1750 rpm = 2187 rpm
Either the tachs are way off, the gear ratios are not what Ram published and you are not running in 6th, or it's dropping out of converter lock at 75mph. I see no way to come up with those observations based on published data.
I could question Continental's number on revs per mile, but all the tire brands in that size I checked on Tire Rack are within a few revs per mile of 709.
 

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I have to say as speed increases on my 1500 the revs climb slower as a taller final ratio would suggest. At a steady 80mph engine revs at 2,250rpm.
 

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That is the problem with analog tach, it's subjective. It really looks to me to be slightly more than halfway between 2000 & 2500 rpm's at 75 mph.

Played with the Tremac transmission calculator and came up with 3.86 should be @ 2160 at 75 mph. The 3.43 should be @ 1920 at 75 and the 3.16 should be 1770 at 75. The other problem we have is it's an automatic with a fluid coupling. Torque converter lockup should eliminate the variables but who knows.
 

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I can add a couple of things:

1. The trans will happily tell you what gear it's in if you kick it into manual mode and shift it for yourself. But what it won't tell you is if the converter is locked. On mine, it seems like the lockup isn't very on/off but rather quite fluid and "slippy". There's no way to truly confirm that it's in 100% lockup that I know of without the factory tool in the OBD port, but you could (I think) force the converter into unlock by very gently riding the brake pedal. If the computer thinks you are braking, it should pull the converter out of lockup.

2. The point of knowing what the final ratio is is to maximize power or mileage. So the simple solution would be to run a few hundred miles in 5th (via manual shifting) or even 4th, and compare the fuel economy. Probably best to use cruise control, and make your tests on the same road with the same load.

I suspect that the difference wouldn't be as much as you'd think though. Playing around with this in other vehicles over the years, I've concluded that lugging the engine by running too low an RPM burns more fuel than running a few higher. So I would guess that heavily loaded, or on hilly roads, you'd probably end up getting better mileage in 5th than in 6th. The Pentastar, from what I can tell, is much more a rever than a torquer, so it would benefit even more from a staying in 5th.

Rest assured, I'll be experimenting with this alot as time goes by.
 

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Here is a screen shot of an MPG video.
Also the RPM @ MPH in high gear.
This 3500 is so **** quick around town I regularly get the jump on people who do not want to let me over.
By the time they realize I stepped on it and try to react, I'm already far enough ahead to slip in front of them.
 

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Thats so true the PM is quick off the line and passing. The Pentastar is a great engine. Ive had diesels in the past and im sure 174hp in the diesel will be very slow in the PM just like the very slow Sprinters. The diesels will certainly get the job done and be good but not very exciting. The diesel gives up 100hp and gains 30lbs ft of torque. But the pentastar has 90% of torque come in so low very diesel like around 1800 rpm, with more HP.
 

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It's funny; one of my minor complaints about the PM is that it's TOO fast off the line. I think the throttle mapping could use a tweak to make it less jumpy and more controllable.

I spent a lot of time making the decision between gas and diesel, and included in that decision is also the new Transit and the Benz. I can come to no other conclusion that gas is the better choice. Here's some reasons:

1. Today I bought gas at $2.96 in Toledo. Diesel is more consistent, but right now it's around $3.85. For the actual cost to be equal, a diesel PM would have to get 28.62 mpg (where the gasser gets 22mpg). It's possible that the diesel will hit that number, but that just gets you to even. You can buy an awful lot of gasoline for the $4000 price difference. Don't forget to add in DEF too.

2. Even if the diesel got 40mpg, all it would take would be ONE repair or normal maintenance visit to the dealer for service to wipe out that savings. And such an oddball, European, and rare engine would mean that only the dealer could service it, and even then the mechanic would be ill trained and probably incompetent. This unaffordable service is what makes people HATE the Sprinter so much. And I think it will happen with the Ford too in the long run.

3. Other than mileage, the main feature of a diesel is torque and towing. The PM won't tow or carry any more with the diesel (so far as I can tell). So as long as the gas engine is "enough", you gain nothing with the diesel. The pentastar is more than enough. I could honestly get by with 100hp less and not complain. It'd still be "faster" than most vans/trucks, and it'd still be fast enough. I'm hauling freight, not drag racing.
 

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100% agree. Pentastar is a really good well engineered engine. No EGR valve, among the many well engineered components of this engine. The pentastar will easily last 500,000 plus miles. Very fuel efficient. I am confident in predicting that the diesel will get about 4mpg better than the pentastar. People will post mileage all over the board for the diesel when its released but each persons driving habits and enviromemts are different and given identical enviros Im sure 4mpg will be about right. Given that at least half of the year if not most of the year, diesel is .30 cents to .80 cents pricier, the gas due to its high efficiency is an advantage . Just a few years ago we never had gas engines this efficient. The pentastar is the game changer and is efficent. Also I have driven medium duty trucks with the Manumatic transmissions and they shift quite slow. I hope the diesel trans will shift better than those trucks but the European current Ducato manumatics are slow shifting with delays between shifts. Im sure owners of diesel promasters will be very hapoy because this is one amazing van.
 

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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.
My scan gauge reads 1800 rpm @ 60 mph (2500, 159 wb, tall) I guess I have the 3.86!
 

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Discussion Starter #36
Ok, just want to bump this up again...hoping someone with a 2500 might chime in as to MPG. So far, much of the discussion is theoretical calculations of gear ratios. MPG reports for all models so far seem like they are either around 16 or around 20, but I'm not seeing a correlation with any models so far? I'll be happy if I get a van that averages 18-21, not at all happy if I get 16-18.

It seems like the dealers are getting more flexible in their pricing as the year winds to a close, and I'm still trying to choose between the two--the price difference seems to be approaching marginal differences. Don't really want get a 2500 if the 1500 will get better real world mileage, but some of the 2500s on the lots near me have a few minor options I'd like.
 

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I'm getting about 16-18 on my 159 wb, tall, 2500 and I'm more than happy. My diesel Sprinter got 19-20 tops so I figure I'm about even.

You can't really tell from the computer display, you have to do the actually math to make any real sense. In my case in 7292 actual miles driven I've burned 443.18 gallons of gas for an average of 16.45 mpg. Sometimes I get as high as 19, usually 16/17. This includes towing a car on a tow dolly for about 1500 miles out of the 7292 and about 50/50 highway/in town driving.

I'm a lead foot and I never worry about or try to save gas, BTW.
 

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I've left my "tripmeter B" alone, so it is essentially lifetime consumption. Right now, it says 11.2 L/100 km. That is right at 21 mpg US. This is with a lot of steady-speed 105 km/h highway, but it also includes doing that through VA, TN, and NC. This is for a 136" low roof 1500.
 

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It might be close but it's only an estimation in reality. You can only find your real mileage by averaging your exact mileage driven divided by the exact amount of fuel used over a reasonably long time, not jus a few fill ups. Numbers don't lie. You can't trust the trip computer to be any thing but close, certainly not on the money.
 
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