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Discussion Starter #1 (Edited)
This review really got my attention. It tipped the scales from "maybe" to "do it" and I called a dealer to start the negotiation.

2014 Ram 1500 EcoDiesel vs. 2014 Ram 2500 - Sibling Rivalry - Diesel Power Magazine All Pages

Later edit. Math works out closer to 19% improvement. My mistake. To put that in perspective....
2006 F-150 got 7mpg towing 24' enclosed trailer.
2000 F-250 got 13.5mpg towing 24' enclosed trailer.

I don't figure that it was much of a tow test tho. 15.8mpg out of a 2500 Ram is pretty good mileage. My buddy pulls the same size trailer as I and he gets 12.5mpg. It's worth noting when a modern (2010 RAM 12.5mpg) engine gets worse mpg then an older (2000 F-250 13.5mpg) engine. EPA has been hard on diesels.

All these mpg figures, btw, are @65mph on flat terrain.
 

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You could probably nit pick a couple figures but there's lots of information to be had.

One surprise I must have missed is how high an rpm engine the 3.0 is for torque. I thought it was 1,000 rpm less for max torque. Guess I thought wrong.
 

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Discussion Starter #4
I agree. I would have expected peak torque around 2500rpm. Also, the fact that the dyno curves used different X and Y axis makes it very hard to visually compare the two curves. That was badly done. If you put two curves right next to each other, clearly you intend for them to be compared. But then you change the values on the axes and comparison becomes hard.
 

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You could probably nit pick a couple figures but there's lots of information to be had.

One surprise I must have missed is how high an rpm engine the 3.0 is for torque. I thought it was 1,000 rpm less for max torque. Guess I thought wrong.
That's where it makes max torque at the wheels, Although it may be 325 lb-ft at 3,160 rpm it could be making [email protected] 1,800. Also the Dyno is flawed because they did the comparison in 6th gear with the 1500 and but didn't/couldn't lock it in there to begin with so the basiclly started driving on the dyno until it hit 6th gear then mashed the throttle. Although I understand they did that to get it into 6th gear where the final ratio is closer to 1:1 it didn't help. Notice the graph doesn't even start until 2,800rpm/
 

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this is exactly what I wanted to see. I was hoping I would be able to return 20mpg towing my 6000-6500lb boat.
 

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Discussion Starter #7
That's where it makes max torque at the wheels, Although it may be 325 lb-ft at 3,160 rpm it could be making [email protected] 1,800. Also the Dyno is flawed because they did the comparison in 6th gear with the 1500 and but didn't/couldn't lock it in there to begin with so the basiclly started driving on the dyno until it hit 6th gear then mashed the throttle. Although I understand they did that to get it into 6th gear where the final ratio is closer to 1:1 it didn't help. Notice the graph doesn't even start until 2,800rpm/
Can you elaborate on that a bit? I'm not sure I understand. I know about dyno tests on manual transmission cars, but I don't know anything about doing it with an auto.
 

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I can assure you my Cummins tows my toy hauler and gets 12 - 14 mpg. Never any better and sometimes down to 10 mpg. I putz along at 65 mph also and people vote me #1 often as they pass.

Soon as my new one comes in I/we will know.
 

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Can you elaborate on that a bit? I'm not sure I understand. I know about dyno tests on manual transmission cars, but I don't know anything about doing it with an auto.
Not sure if they couldn't or wouldn't lock it into 6th gear. Meaning they had to drive on the dyno like they were going down the road until it got to 6th gear then mashed the throttle. In doing this you don't get a reading right off idle like you would if you just put a manual in 4th while idling and then hit the throttle.

What happens is you're already in the rev range like shown on the graph. It seems like what they did was a OD lock out, the transmissions are double overdrive transmissions so the top two gears 7th and 8th on the 1500. I looks like they locked, or turned off OD and did manual until the truck got to 6th but sometimes the truck won't let you manually shift too early or low in the rpm.


I'm sure there are ways around this but it seems they were strapped for time. And just wanted some numbers. There will be much better dyno graphs later on. Based on the graph I'd expect the 1500 to make about 350lb/ft to the wheels @1,800 rpm
 

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Thanks for sharing the article. It is very informative. I am subscribing to the magazine. Lots of great information there.
 

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I know they did it to be consistent, for comparison sake. But one thing to remember is they towed a trailer that was 105% of what the 1500 was rated for and only about 40% of what the 2500 is rated.
 
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