Crazy question--convert 07.5-12 CTD to DEF like the 2013/14?

[AHarris]

Was wondering if it has ever been talked about, given the advantages of using DEF over the original system for better mileage, DPF life, oil life, and less soot in the engine? I'd be curious to see what some of the more seasoned Cummins experts on this board have to say about feasibility?

 

[Simplysmn]

I would say for what it would Cost you in part's and time and everything else just Drive the thing and Enjoy it . It would take Year's to recoop what your going to spend to convert it . but that's just Me . I don't believe in Deletes or anything like that Either .

 

[EDankievitch]

I asked the Cummins Engineers that very question. They liked the idea but that's as far as it went.....

 

[Joseph Donnelly]

It is not practical, even if legalities are not considered. The new engines have different timing, combustion chambers, cam, etc. Costs would be high also. Engine software (ecm) is very different and the new ecm is different with more connections.

 

[TLane]

Actually, it's quite simple to convert. You just load the bed of your old truck up with cash, drive to the dealer, and they'll be glad to assist you with converting. You can change the color of the truck while your at, and even switch between 2WD and 4WD, single rear wheel and dually, etc. It all depends on how much cash you have in the back of the truck... :-laf

 

[RUSSELL5000]

I have been thinking about this long and hard as I have a 2012.



As Joe Donnelly points out there is a lot involved - more than I understand as a newby. Here is how I figure it, and why I would not do unless a high quality "kit" was available at low cost from an aftermarket proivider (which hardly seems likely).



There are a couple of earlier issues in the TDR which examined the costs associated with the emissions systems in the 2007. 5 through 2012 trucks. What I got from these is that more frequent oil changes, EGR cleaning service, and a decline in fuel economy due to DPF regeneration are the increased cost drivers. The fuel ecomony issue is the main cost, of course. However, as the articles do a very nice job of illustrating, the fuel economy cost is pretty marginal when the truck is working hard (hauling or towing something heavy).



So, I think whether this makes sense depends on how you use the truck. I only use my truck on the highway going somewhere, and normally towing my travel trailer. As I have learned on this forum, the box-like shape of my travel trailer is impacting my fuel economy more than the DPF regenerations. In fact, I think (may be wrong) I would do a lot better in fuel economy by careful selection of a travel trailer than I would by getting a new truck with the revised DEF/SCR emissions approach. Unless a kit was available at a low enough cost to offset my increased costs (negligibly higher fuel costs, more frequent oil changes, and EGR cleaning) I don't think I would bother.



On the other hand, if the truck is an every day commuter, kid-hauler, grocery-getter, etc. , the fuel mileage penalty due to DPF regeneration is far higher, and it may make sense if some type of conversion kit became available.



Anyhow, my thoughts from a non-engineering but dollars and cents view.

 

[rscurtis]

Assuming such a kit was to be available from a hardware and software standpoint, it would still have to pass muster with the Punishment Agency. That would be the death of it right there.

 

[Joseph Donnelly]

I think you would end up ahead selling the 2012 and buying a leftover 2013 with the $4000 rebate and other dealer incentives. You also get the chance to have the Aisin trans, much more HD frame, suspension, etc. on the new 3500s.

 

[RUSSELL5000]

Joseph Donnelly:



There may be others in my position who are pondering whether to trade in the recent truck for a 2013. I did the following analysis based on my driving: 10,000 miles per year, mostly towing my travel trailer, with two oil changes per year. I assumed that my fuel mileage would increase from the current 12 miles per gallon to 14 miles per gallon. I also assumed I would do one oil change per year rather than two. I used the Ram website tools to get the trade-in value and 2013 costs. Both trucks are base trim (ST or Tradesman). I assumed I would keep the existing truck ten more years.





10,000 <= miles per year

12 <= current fuel mileage per gallon

833. 33 <= gallons of fuel per year

$3,333. 33 <= fuel cost per year @ $4. 00 per gallon



14 <= revised fuel mileage per gallon

714. 29 <= gallons of fuel per year

$2,857. 14 <= fuel cost per year @ $4. 00 per gallon



$476. 19 <= fuel savings per year



$550. 00 <= oil change savings over ten years ($55 per year times ten years)

$4,761. 90 <= fuel savings over ten years (amount above times ten years)

==================

$5,311. 90 <= total savings over ten years





$35,000 <= KBB Trade-In Value of 2012 2500 CC 4WD



$48,500 <= 2013 3500 CC 4WD Dually w/ AISIN

$4,000 <= Rebate

$4,000 <= Dealer Discount?

==================

$40,500 <= Net Cost





It looks to me like I might break-even on the deal if I can get the 2013 3500 dually w/ the Aisin transmission from a dealer for $41K and get $35K trade on my truck. This is before sales tax (6%, or roughly $2,400 where I am at) and document fees. Also, I would have to see my towing fuel economy increase by roughly 17%. All of this ignores inflation and present value for simplicity.



Does this make sense? Are these assumptions (fuel economy, trade-in value, cost of new truck) realistic? This all seems optimistic to me.



Thanks much!



Russell

 

[TLane]

You forgot to add in the cost of DEF, which is going to eat up most of your fuel savings. And I think you have to change the oil every 6 months to keep the warranty in effect, so you won't save much there either.

 

[RUSSELL5000]

TLane - I just checked the manual, and oil changes are specified every six months on the maintenance schedule. So I am changing oil twice a year regardless, and so there would be no savings for me.





I am kind of spastic about oil changes, and I would probably change twice a year whatever truck I have, so for me in particular it would not help.





Isn't there a net savings on the new trucks in fuel cost even aftyer considering the cost of DEF?

 

[rscurtis]

Using Joe's numbers, you're saving about 7 gallons of fuel every 500 miles. Assuming DEF consumption at 500 MPG, every dollar spent on DEF saves about 7 dollars on fuel, assuming they're the same price. Regarding oil changes, resist the temptation to over-service the engine and take advantage of those savings too. I change the oil in my signature truck about every 18K miles, and I'm still over-servicing it according to oil analysis reports.

 

[K5IP]

Also remember, If you do upgrade, the value of your new truck would be higher, in the resale market, than the non DEF units.
Rog