Fuel dilution and Urea (DEF)

[TDickerson]

I will be buying my new truck in the 2012 model year when I come back to the states next year. I had a 1997 12 valve and want to buy a new Dodge. I am so confused and concerned with this new stuff on the diesel engines that I am about ready to go with a gasser. I have a 7K pound TT I pull and would like a diesel though for future upgrades. So, Ford and Chevy seem to have the UREA setup that is claiming better fuel mileage. But, how in the heck are you getting better mileage with this stuff being pumped into the exhaust system. Doesn't make sense to me. The Chevy guys are saying dodge is pumping too much fuel in the engine during the regenerations causing washout and considerable fuel in oil dilution. But, they have the DPF filter too and have the regens also. Are they using less fuel during the regens and fixing it through the DEF. My number one concern with the Dodge is the fuel dilution problem that appears to be happening. Are Ford and Chevy not having fuel dilution problems? I'm totally confused. Oo.

 

[rscurtis]

All three of the manufacturers use the DPF to mitigate particulate emissions. Dodge is presently using a NOX adsorber catalyst to control NOX instead of using the urea (SCR) that Ford and Chevy are using. The problem with it is that it requires almost constant regeneration (for the adsorber), and in addition to that, a lot of EGR. The EGR will require that the DPF be regenerated more often, resulting in the increased fuel use when the cylinders are dosed with extra fuel to heat it to its regeneration temperature.

This method of heating the catalyst and the DPF can lead to fuel dilution.



The Ford and Chevy require fewer regenerations because of the lower rates of EGR they are using. Use of urea also allows the timing to be advanced toward its optimum setting. This = better fuel economy.



The Chevy goes one step further, it has a ninth injector in the exhaust system for fueling regeneration, thus eliminating the risk of fuel dilution. IMO, this is the best system of the three trucks at this time.

 

[TDickerson]

Thank you for the information, that was very helpful. I am somewhat impressed with the Duramax and have been looking at those as an alternative to the Dodge. I know they all have their issues, but when you are shelling out big bucks for these trucks now, you want to at least figure out what is going on. I am just hearing so many complaints on this fuel dilution thing that it is really putting me off of the Dodge.

 

[Simplysmn]

Just remember that when you buy a chevy you are supporting Japan cause that's where the motor is built for Isuzu plus gm is Goverment Motor's no thank's

 

[rscurtis]

A lot depends on how long you plan to keep something. IMO, the Cummins engine, even its latest iteration, will age better than the Dmax or the Scorpion. It is more user friendly for DIY repairs also. If, OTOH, you tend to lease vehicles or upgrade every several years, any of the three would be an option.



It is also possible that by 2012, the Ram will be using SCR, leaving Navistar the only holdout with their heavy EGR system.

 

[MannyC]

re japan comment

gm motors are built in japan, our dodges are built in mexico. both gm and dodge took govt $ so they are on equal footing in my book. i would have bought ford, but my past ford purchases were terrible. also, driving around with a gigantic super duty script on the back -pronounced 'doodie' by my young boys makes them giggle every time they see one.

 

[PLefever]

there are some fellas that are probably better versed than I on the subject, but my understanding is that by treating the exhaust they can throttle back the egr? the cab and chassis have urea, I can tell you that the mileage is impressive for this kind of truck and I haven't regened yet but only have 2500 miles, my ford regened about every 200 miles or so and poured so much fuel down the exhaust they were recalled once for starting fires. when I took the dpf off the ford and put on the chip, I didn't set it right and it tried to regen without the dpf and made so much smoke my wife seriously thought I lit it on fire. in retrospect that would have been a good idea. . ha

I understand the duramax has moved an injector into the exhaust for dpf firing instead of making the engine really rich, (sounds like a good idea)

perry

 

[RonD]

I thought I would make a correction on this post, 1st of all the Duramax was a design of Isuzu, a heavy weight player in Global Diesel engines, GM owned 60%, Isuzu 40%, as of a year ago GM owns 100%, the engines have never been built in Japan, only Dayton Ohio. As far as Government Motors, Chrysler is the same as GM, maybe worse, if your concerned about USA products look at a Ford, no government involvement, Super Duty's all are built in Kentucky.

 

[Metalaram]

if your concerned about USA products look at a Ford, no government involvement, Super Duty's all are built in Kentucky.

The new 6. 7L Ford diesel motors are built in Mexico. They are then shipped to the US to be put in a truck.

 

[ChrisOlson]

Well here is some interesting reads
Chevy DuraMax
How It's Made: The Duramax Diesel Engine - Diesel Power Magazine


FORD 6. 7 diesel
Ford's new diesel truck engine to be built in Mexico, not Brook Park | cleveland.com

and finally our beloved Cummins 6. 7
How It's Made: Cummins 6. 7L Engine - Diesel Power Magazine

The internet is a remarkable place

chris

 

[ChrisOlson]

HMMM

More interesting read
dodge only owes 10% of the money borrowed

GAO: Gov't Won't Get All Auto Bailout Money Back

GM owes 61 precent?

Chris

 

[TDickerson]

There is some interesting reading about the diesel engines, especially the one about the Duramax. "The most significant is that it hot-tests 100 percent of the engines it produces". Cummings only does random sampling. I'm especially disappointed that there is very little discussion on the new pollution systems and why they have elected to go with the system they went with. GM does explain it the best and their explanation is the most logical and honest. Especially, going with the 9th injector and not allowing their system to contribute to cylinder wash out and fuel in oil dilution. That is what concerns me the most. We need to be more assured that what they are doing is not going to present massive problems for these engines down the road. Before I shell out 50K or 60K for one of these trucks I want that assurance, and I don't feel there has been enough research and development on these systems rather than some trial and error, and just getting something in place quickly to meet the requirements.

 

[Metalaram]

Cummings

UGH!!!



Cummings is a town in Georgia where the TDR/Geno's is from.



Cummins makes the motors in our trucks:-laf

 

[swordfish]

ChrisOlson, great read and great info. Thanks.

 

[TDickerson]

"Cummings is a town in Georgia where the TDR/Geno's is from". LOL, can't believe I did that. Just came back home from a new years party. Must have been the refreshments. I'm in Germany. Happy New Year.