I'm interested in improving aspects of my Ram; a 2012, 2500, SLT, Crew, short bed, 2WD, Allison, CTD, 4.10:1, about 14K miles... bone stock drive-train.

Its my daily plus I pull a Hyperlite 29HFS at about 9000#. Even stock it is a joy to pull with such a capable truck. I have taken 2 trips at about 5K miles, but probably will only pull the TH about 1K a year.

Only mods are Rhino liner, oval tube side steps (which I have lit up with LED strip), towing mirrors, and I have cameras on both ends.

With the price of diesel higher than when I was planning to buy and not happy that it is, I am interested in improving MPG while not towing and especially would like to reduce or eliminate the regen cycle. I really don't want more power, but if making improvements gets me more, I will understand.

I would like to swap out the 4:10 or install taller tires, if it makes sense to do and possibly a tuner and FASS system. I have a S&B air cleaner ordered since my original filter is crying.

I read that with the addition of a alcohol/water injection system (and the other mods) regen is nearly eliminated; even keeping the DPFs. I want to hear from those who are of like mind and have real world experience.

 

You don't have an Allison transmission, unless someone swapped it in. Allison is a division of GM Powertrain.

Your trans is most likely the Chrysler 68RFE. It's a good trans. I didn't like the stock programming on my 08. H&S's Overdrive software made a night and day difference.

Regearing is going to cost you about $2000. I had 3.73 gears in mine and never wanted taller, even towing ~14k pounds coast to coast. You might find someone interested in swapping axles, which would be much cheaper.

 

Horatio, you are right. I sold my Chevy 1500 that had some version of a 6 speed auto, and I think it was an Allison. I wrote Allison hastily. It is a 68RFE 6 speed auto, some say an Orion built in Chrysler's Kokomo IN plant. 4th is 1:1 so 5th and 6th are both OD. I'm turning 2000 RPM at 70MPH, so that isn't really that bad. Swapping to 3.73 probably wouldn't be worth the work.

I really hate the regen, and the 5 to 6 MPG instant ready drop in MPG. I drove to Tampa a couple days ago; not towing, it averaged 17.5... that was after a regen at the start of the trip... about 20 miles or so; then it went into regen again near the end of the trip, while driving at a steady 70MPH or slightly higher), which before the second regen it was back up to 18.4. I am confident that without regen, I would have averaged 19MPG. My truck goes into regen almost every trip.

When I bought it, I opted for the extended warranty, so really cant risk messing with it... I also did some math, and if my numbers are right, it would take 175000 miles to break even on the money to "fix" the issue.

I can't see how burning many extra gallons of fuel, dumping it into the atmosphere... would somehow help the atmosphere. It must be way over my skill level.

I read somewhere that a tuner, an air filter, a FASS pump, and water injection could cause it to burn so clean it might not regen again. Improving MPG by 1 to 3. I am not sure I believe this. It would cost about 2500 bills to find out; a gamble I am not willing to take.

A rep of a company who does gas tuning on RVs, said the best cost effective way to 'gear up' is to go to 19.5 commercial tires that are taller, but not so wide. After looking at the cost and what will probably be a rougher ride, this doesn't seem like a good thing either.

So, I'll just drive it and cuss the government for messing with something that should't have been messed with.

 

As far as I know, GM only puts the Allison 1000 behind 3/4 and 1-ton pickups/suv/sut with the diesel (and the big-block when it was available).

It really isn't any better than any other manufacturer's tranny. The higher end transmissions are great, but they're not in the GM trucks.



And 19.5's are great and all, I thought about it when I had my 08, but after seeing tires cracked all to hell after 2-3 years down there in Sarasota, it didn't seem like all that great of a deal if I had to replace tires due to rot with 70-80% tread left. Especially when they cost as much as those things do.

 

Not sure where I got Allison on the brain. I knew the Diesel HD trucks came with them, and being 6 speed I somehow assumed they also must have made a lighter duty version; without researching it. I also think a salesman mentioned the name. If you can't trust a salesman, who can you trust?? I now see it was a 6L80E. I really like he tranny, BTW. I also read that HD trucks with gas engines (to 8.1L) came with the 6L90. Whatever it was it is "history" so to speak. The weak 2010 I had has soured me away from GM. It was rated to pull 9500 lbs, I think, and it struggled with 3500# in the mountains. It would pull more, but you have to manually shift and keep it screaming. I was also told it had 3.73 gear sets, which i don't think was offered that year, in a 4-wd Z71 half ton.

I do appreciate your input about how the heavy duty tires didn't hold up for you. I would like to ask, if they gave you better fuel economy?

 

I just got 22.7 hand verified (the lie-o-meter wasn't really off by much as it read 23.1), on a long weekend trip from central Florida up to my farm property in south Georgia.

The '13 and '14 trucks seem to be getting a bit better MPGs due to the DEF fluid systems requiring a lot less regens.

Over-all getting about 18.5 on my commutes to work which is about half in town, half 55 mpg four lane...

 

I never bought the 19.5's. I thought about it, seeing as the benefit of a decade worth of mileage was attractive, however after working at the dealership for a while I was seeing passenger tires (michelins, continentals, etc) that were dry rotted to hell after 2-3 years, and decided against it.

 

my lie-o-meter used to be dead on accurate with hand calculations...then I started modifying the performance of the truck and well..its not so accurate anymore...