Question for owners of late model Ram 2500 6.7 Cummins Diesel Owners

[slowmover]

The changes culminating in the 2014 models make for the first time since mine was built (2004) a truck worth upgrading to. But not before.

[SteveH]

Ya know, the link that Bill provided says they changed to a new wider range transmission, which would support the increased towing weight rating, but I've been surfing the window stickers of trucks on the dealer's lots, both '14's and 15's, and they all spec the exact same transmission that is in my truck, the 68RFE.

Think I smell a rat.

[jcl]

The way I read it the wider range transmission was the Aisin in the 3500 models.

They don't ascribe percentage of tow rating increases to each modification, they just list all of the changes. Some might apply to a specific model, and not others.

[tjdonahoe]

REALLY!!! Imagine that?

[crisen]

Unless it changed just recently, the Aisin was an option on the 3500, didn't check the 2500 as I was pricing what a new one would cost if I decided to get rid of my '08 3500. My recollection is that the Aisin was around $2500 as an option so don't know how many dealer vehicles are ordered that way. As to mileage my truck is a manual with 3.42 gears and od ratio is not the same as the auto. We averaged 12.6 for our last trip outside, 15000 miles. However with winter grade fuel and extra warm up times it drops below 11 and there are quite a few thousand miles in that average with those conditions. Unloaded at 65 on two lane roads is 19 pretty consistent, never quite broke 20.

[slowmover]

Originally Posted by SteveH

Ya know, the link that Bill provided says they changed to a new wider range transmission, which would support the increased towing weight rating, but I've been surfing the window stickers of trucks on the dealer's lots, both '14's and 15's, and they all spec the exact same transmission that is in my truck, the 68RFE.

Think I smell a rat.

No, you're hung up on numbers that are free-floating by their very nature. If you want more understanding of "ratings" it is that brake performance is tied to it.

Heavier loads exact greater demands on the driver. Americans believe they are good drivers, yet I see that so rarely I wonder if it even exists any more. Any around this forum those who slam the brakes more than once in 10k miles are not good drivers. In our part of the country those who go through brakes on these trucks in under 70k are not good drivers. It's a reality the OEMs must accommodate.

Load the truck to GVWR and the braking is different. As I said, give a junior engineer a spreadsheet and an algorithm to work up rating differences in spec. The feel of the truck is part of that. Making allowances. Free floating, and can be adjusted to suit.

And year by year changes can be accounted by further testing. Materials changes. Tire compounds. Drivetrain improvements. Software adaptations. Etc. Marketing is blamed, but risk analysis is done. It is not carved in stone.

Unlike tire/wheel ratings. If you see a real jump then check those spec's.

In a Class 8 truck there is a very real difference between being loaded at 76k versus 79k+. Much more so than between the former and under 70k when it comes to braking. Aforesaid dumb Americans won't adjust their driving to suit. Still at 65+, still without adequate following distance and without allowance for fatigue and weather. The old mantra of road, load, traffic and weather. Not equipped with thinking skills, IOW.

For those, then, caution should be foremost. But is unlikeliest given their nature.

[tjdonahoe]

Then you go up to 100,000 ,you have 2 more axles with brakes, a little wider shoes on the front axle for the extra weigt ,usually 15000lbs....no worries..

[SteveH]

Today I finally talked to a truck "expert" at one of the local dealers, and I asked him specifically what Chrysler had changed on the trucks that so drastically increased the tow rating and the GCWR. Basically, he did not know, but that did not stop him from trying to BS me in true salesman form.

Finally he said he would consult a certified technician and get back to me. When he called back in about 20 minutes he told me the engine had been tuned differently (DEF injection, and this I knew), the air intake box had been modified(VERY seriously doubt this makes any significant difference), the frame had been strengthened ( this I also knew from the page Bill linked), and the truck had "dual radiators".

Dual radiators???? This I must go see for myself. I suspect he's piping me a line of sunshine. These things with the same displacement engine, the same torque spec, the same differential gear ratio, takes the truck from 17,000 to 25,300lbs GCWR? Let me up!

[BAB]

I've put 19,000 miles on my '14 Ram Laramie 2500 4x4 with the 6.7L Cummins. About 17,500 miles have been towing. During a 28 day trip last summer I can only say it proved itself way beyond my already high expectations. I averaged 14.8 MPG overall, and added about 7 gallons of DEF on the voyage. Fantastic performance through the Rockies, and the 68RFE transmission was flawless. Very happy Ram owner!

[slowmover]

The cooling system changes on all brands have been extensive. IIRC in 15 Ram is back to one. There is nothing simple on any of them. All the more reason to hold out for the Aisin trans and full air ride, ha!

[SteveH]

This morning I was again looking at the Ram Trucks towing capacity guide, and it seems they rate a truck's max towing capacity while it is also carrying it max payload.

So I went back to my weight tickets, and see where we actually only carry about 500lbs normally in the truck, so I figure this might go as high as 1,000lbs. The max payload of my truck is 2300lbs, so by the Ram chart you could add 1300lbs to the max towing capacity.

This would get my max towing capacity with the max payload we would ever carry, up to about 10,800lbs. This is within a couple of hundred pounds of what the weight tickets indicate we are actually towing. Don't think a couple of hundred pounds either way is a big deal.

However, this does not address the fact we are over the GCWR of this truck by over 1000lbs......confusing.

But then I keep going back to the thought that at least it's much better than a minivan.

[Bill M.]

The only downside I can see to changing the gears is the expense since it is a 4x4. It is bound to pull that heavy a trailer better with the 3.73. I do not think the 34' trailer has the same bearing/wheel/tire problems as the 30' with the slide. Of course if a new truck is in the cards....

[RickDavis]

I would not even consider the gear change. I used my 99 with 3.55 gears and much less horsepower to deliver trailers all over the U.S. Most of them large fifth wheels with an occasional 34 ft AS in the mix. Performance was satisfactory . I still have the truck with almost 600k on it.

My 13 2500 4x4 crew cab long bed with 3.42 has much more power and delivers almost the same mileage. (around 15 with the 24 I normally use.) and there are no longer any hills in WV.
I see no cause for concern.

[jcanavera]

While this doesn't specifically address your model of truck, I did go through the decision about the rear axle back in 2003 when I ordered my new van. At the time I was pulling a 6,000 lb Safari with a 5.7 liter Chevy Express 1500 passenger van. That van had a 3.42 (rear axle). The van was rated to tow 6,500 labs. We towed in third rather than OD based on the towing guidelines in the owners manual. Milage when towing was between 11-13 mpg dependent upon road and wind conditions.

We replaced that van with a 6 liter GMC Savana 2500 passenger van. I decided to order the optional 4.10 rear axle which gave the van a 9,900 lb towing capacity. That van per the owners manual allowed towing in OD provided that you weren't experiencing a lot of gear hunting due to road conditions. With that van I changed the trailer to a Classic slide out which typically weighs in at 8,500 lbs.

What surprised me is that going to a bigger engine, heavier van, and heavier trailer did not affect towing gas mileage. I still average between 11-13 mpg towing. The big difference was solo driving in which the bigger heavier taller geared Savana gets about 5 mpg less than my Chevy Express. Obviously the higher RPMs that the Chevy needed to tow had a profound effect on gas economy. The higher gear ratio on the GMC while causing some higher RPM's still allows me to use OD which offsets those RPM's and gives me plenty of power to handle the higher weight of the trailer and the van itself.

They key to me is not only the larger engine, taller axle of the van, but the towing capabilities of the transmission. By nature the 3/4 ton van mated with the 6 liter engine GMC provides a much more robust transmission which in turn with the axle allows me to use OD on most road surfaces.

So the bottom line is changing out the rear axle can provide more towing capacity. You do have to factor in the capabilities of the transmission and the vehicle itself. Obviously the inherent factors of going from a half ton to a 3/4 ton tow vehicle also have contributed to the overall towing experience.

For some, while the axle change may have some performance improvements you have to caution whether the rest of the vehicle and its components are up to the capability of the load you are carrying.

Jack

[Lance M]

SteveH,
Maybe this will help, maybe not, but when you go to the RAM towing site, there is a red button "LOOK UP MY VEHICLE" (2009 and newer) that will open up a popup window where you can enter your truck's VIN and it will show what RAM lists as the max payload and max towing.
Maybe it is different from the pdf you are looking at above.

[crispyboy]

SteveH - I would highly recommend you subscribe to the Turbo Diesel Register Forum. Anything you desire to know about these trucks can be found there.

Here is a real life example I can give you.
My truck is an 2009 with the 6.7 engine, (350 hp, 650 torque) 68RE transmission, 4x4 with 3:73 gears. I mainly tow in 6th gear with occasional downshifts to 5th here in the mid-west on the hills. I usually drive 65 to 70 mph while towing. Towing fuel mileage is 11-13 depending on the terrain and headwinds. GCWR on this truck is 20,000 and max trailer is 12,850. Solo mileage 15-16 in town and a high of 19 on the interstate. All stock.

I have used my brothers truck on a few occasions. He has a 2012 with the 6.7 engine, (390 hp, 800 torque), 68RE, 4x4 with 3:73 gears. Towing mileage is 11-13. Solo mileage 14 in town and a high of 18 on the interstate. All stock.
Not much difference mileage wise in the trucks but his truck definitely has more seat of the pants power.
I wouldn't worry too much about the numbers on your chart. Gear ratio's are the only difference for the GVWR. You 3:42 gear set should only hurt you when starting a heavy load on a steep grade.

Do you think you were getting some axle wrap going on while starting on such a steep hill? It is pretty easy to spin the wheels on my truck when starting on a steep grade while hooked to my trailer. Feather the accelerator until the load gets moving.

There are a lot of differences in the 68RE transmission and the newly available Aisin transmission on the newest trucks. I understand it to be a true medium duty truck transmission that weighs much more than the 68RE. Also the the frames and engine programming has all been changed on the newest models along with the newer SCR emission technology.

Probably not worth the hassle to change ratio's unless your always in steep territory.

[crisen]

Originally Posted by SteveH

This morning I was again looking at the Ram Trucks towing capacity guide, and it seems they rate a truck's max towing capacity while it is also carrying it max payload.

So I went back to my weight tickets, and see where we actually only carry about 500lbs normally in the truck, so I figure this might go as high as 1,000lbs. The max payload of my truck is 2300lbs, so by the Ram chart you could add 1300lbs to the max towing capacity.

This would get my max towing capacity with the max payload we would ever carry, up to about 10,800lbs. This is within a couple of hundred pounds of what the weight tickets indicate we are actually towing. Don't think a couple of hundred pounds either way is a big deal.

However, this does not address the fact we are over the GCWR of this truck by over 1000lbs......confusing.

But then I keep going back to the thought that at least it's much better than a minivan.

Steve,

That is not how I read the towing guide. If you open the pdf file note number 3 says "Payload and maximum trailer weight are mutually exclusive." Which I read as you can't do both at once.

Then I went to the calculator with load slider and put in the following truck,
2500 SLT, Crew cab, 6.7, 4x4 and it lists curb weight of 7700

then I added 2 passengers for 300 lbs and it set slider to 0 cargo load and it shows max tow of 17150. This give makes the truck 8000 lbs and a 25150 gcw

I then left the 2 passengers and set slide to the maximum load in the truck which is 2165lbs, or total truck weight of 10165 and it reduces the max tow to 14985 this adds up to 25150 gcw

What I did notice was that the numbers in the pdf and the numbers in the sliding calculator or not the same by a few hundred pounds, but it looks like gcwr is the governing number which is how I understand the definition.

[mefly2]

2012 Ram 2500 CTD Laramie Crew 4x4; 3.42 ratio, 68RFE AT ... we bought it new (planned as the last truck purchase) because it was the only diesel brand that did not require DEF (at the time). Our mileage was 12-14 pulling the EB25 at 55-60 mph - the hills and mountain passes were absolutely effortless ...that was BEFORE the EPA recalls for re-programming. Then, the mileage dropped off as did the power. Subsequent returns to the dealer did nothing (they didn't even complete the front end recall after 1.5 years). Now driving something different.

[SteveH]

Originally Posted by Top

SteveH,
Maybe this will help, maybe not, but when you go to the RAM towing site, there is a red button "LOOK UP MY VEHICLE" (2009 and newer) that will open up a popup window where you can enter your truck's VIN and it will show what RAM lists as the max payload and max towing.
Maybe it is different from the pdf you are looking at above.

Yes, Lance, that is where I got my information. Thanks.

[SteveH]

Originally Posted by crisen

Steve,

That is not how I read the towing guide. If you open the pdf file note number 3 says "Payload and maximum trailer weight are mutually exclusive." Which I read as you can't do both at once.

Then I went to the calculator with load slider and put in the following truck,
2500 SLT, Crew cab, 6.7, 4x4 and it lists curb weight of 7700

then I added 2 passengers for 300 lbs and it set slider to 0 cargo load and it shows max tow of 17150. This give makes the truck 8000 lbs and a 25150 gcw

I then left the 2 passengers and set slide to the maximum load in the truck which is 2165lbs, or total truck weight of 10165 and it reduces the max tow to 14985 this adds up to 25150 gcw

What I did notice was that the numbers in the pdf and the numbers in the sliding calculator or not the same by a few hundred pounds, but it looks like gcwr is the governing number which is how I understand the definition.

Rick,

If you got to the Ram truck towing spec guide here: Ram Trucks - Towing Capacity Chart

Then select your truck with the body size, bed size, engine, trim level, etc., and then click on the "OPEN TOWING & PAYLOAD CALCULATOR", and then click on the slider, you will see that as you decrease the load IN the truck, the towing capacity will increase.

The slider will not let you go below one passenger, or 150lbs, but it clearly shows with a lighter load, you can tow a heavier trailer, but it also will not let you go above the GCVW rating.