Newer Cummins with Exhaust Fluid

[krazymatt]

I used to own a 2008 Cummins and although I never had trouble with it I heard many folks having issues with the emissions back then. I'm tossing around the thought of getting a 2015 Cummins and I'm just wondering what they're like now with the exhaust fluid? Are they pretty reliable? Does the fuel economy still around 12mpg empty? Thanks for any info I can get on this truck. I understand all Diesels these days have the exhaust fluid but if I got a truck it would be more likely a Cummins as they are better and cheaper than Fords and Chevys usually. Thanks....

[jus2shy]

I'm not the most mellow of drivers I tend to accelerate moderately. I have a few flat footed acceleration events every so often, however I also tend to cruise to my stops and I tend to not fully accelerate when I expect the next light to be red. so it's not like I'm trying to hypermile however I do drive what I think is reasonable. I tend to drive 5 over posted When on the highway. I'm only in my 30's :).

[krazymatt]

jus2shy wrote:
If you are curious about empty srw fuel economy, click on my truck in my signature. It is my entire fuelly history averaging about 18 mpg with 30/70 highway/city.

Wow that's pretty impressive there! I would be very happy with that. I'm assuming your driving style is very mellow?

[Bionic_Man]

Just about all reports of the new 6.7 with DEF show an improvement in MPG vs the '07.5 -12.

Personally, I think you will notice the improvements in the cab much more so than the improvements in the engine.

And even though my preference will likely always be RAM, comparing it to a 6.4 Powerstroke or an older Duramax isn't exactly apples to apples....

[jus2shy]

If you are curious about empty srw fuel economy, click on my truck in my signature. It is my entire fuelly history averaging about 18 mpg with 30/70 highway/city.

[krazymatt]

GaryP, If the 2003 Cummins setup was available today we'd all be ecstatic lol. One thing I do remember about my 6.7L 2008 is that thing had extremely massive amounts of power to tow. That heavy truck would move and set you back in your seat. I've never driven anything else other than an old 24 valve here at work and it ran well but had nowhere near the power of that 6.7 it was a monster. I test drove a duramax once and that was my experience with GM Diesel other than a few half tons that seemed to always be lemons for me. At work we have a 6.4L powerstroke and that thing has some issues it barely has the power to move itself around....

[garyp4951]

The newer Cummins will not get the mileage my 03 does no matter how much def you use, but they sure are nicer inside and out.

[donn0128]

That can be misleading at best. Because of the increases in HP and Torque fuel economy starts out worse. Heck, my 07 6.7L dually with 4.10 rear end returns a steady 17 at 70 MPH without DEF. Towing is 10.5 to 11.5. All hand calculated. That is every bit as good and in a lot of cases better than the new DEF equipped trucks are capable of with "better" rear end ratios.

[krazymatt]

Thanks! Very informative. So it appears these newer trucks might get a bit better mpgs? I talked to a guy who has a construction company and they have a 2015 dually and he said it got 15mpg from the get go so I'm assuming they're maybe going to be a bit better? Thanks...

[BB_TX]

Interesting read here about DEF.

7. DEF will kill my fuel mileage.
Quite the contrary. Because the manufacturer is able to tune the engine any way it wants to, and then allow the SCR and DEF to take care of the pollutants, most manufacturers have discovered better fuel mileage (compared to other smog-reduction systems). Truckmakers claim it improves fuel mileage by as much as 5 percent.

as they are better and cheaper than Fords and Chevys usually
That should get some good comments. :S