305 vs CAT 325

[SLinse]

I would like to see dyno numbers on the 555 and 600. I'm wondering if all the emission stuff(especially the cat) use up the 20hp and 45tq?? I'm thinking that they would Dyno fairly close. Just an outloud thought... ...

 

[DLeno]

The numbers are real, measured at the flywheel, CAT notwithstanding. the only way that power would be "used up" is if the drivetrain itself were more lossy, which is not the case.

 

[Hunter1]

Well, one thing that worries me a lot, is this... ... ... .



They are legal to go to the great state of California!



Now, when was the last engine that was legal to go to California really any good and not totally screwed up with smog stuff?



Just think that over for a bit and ask yourself if you really want a 600 CAT?



Hunter1

 

[2ndgen2500]

arent these the models with an EGR valve? what a stupid ideal... lol any truck with mods, is better than the next. lol my truck wll kill any stock ram? so does that make a second gen more desireable than a 3rd? lol NO! so what if you can mod up a 04 to have similar readings toa 04. 5... its all about what you look for in a truck, and i dont believe a cummins is a cummins with out a little shake rattle and roll, but this is just my humble opinion. although i will say one thing, after seeing what exits my truck, i def would not want that recirculating back through.

 

[klenger]

No EGR in the 04. 5.

 

[2ndgen2500]

oh really ... hmm either way emmissions are stupid, diesels are more environmentally frendly than gas motors. i think people just get the opinion that they arent casue they smoke so much.

 

[Dean Upson]

G3's don't smoke much, if at all.



Dean

 

[DLeno]

Cummins bragging rights

As i was pondering Roberts question regarding the superiority of the Cummins engine re: emissions, it occured to me that there may be a technology limitation that affects the V8s and not Cummins. I'd be interested to hear some discussion and reality checks on this:



Recall that the pilot injection method of cumbustion control does not occur above 2700 RPM. I presume this is an injector technology limitation? 2700 is well above the normal cruising RPM of Cummins but this is not the case for the Ford PSD, which develops its peak HP at 400 RPM higher than the Cummins does. Thus, even though I've never driving one, 2700 RPM it seems to me is not so unusual of a cruising engine speed (for the PSD). This means that multiple injection events are either more difficult or not possible to accomplish at the RPMs most used in normal driving. This of course assumes that both Cummins and Ford are up against the same technology limitation -- the ability to fire the injector fast enough to support pilot injection at high rpms.



So does this mean that Ford has a more difficult task in controlling emissions because the PSD is technologically limited in a way that Cummins is not? Just wondering if this might be part of the reason why the Cummins 04. 5 is able to meet emissions standards by controlling the injection event itself with injector control. -Doug

 

[klenger]

I assume that the reason for turning off pilot injection about 2700 is becasue the events would start to overlap at that point to get enough fuel into the enginer given the shorter duration of a single stroke at higher RPM's. Of course, I don't know crap about how these things actuall work.

 

[DLeno]

well, either way -- if it is a practical timing issue unrelated to the injector itself, or a limitation within the injector technology that prevents high frequency firing -- Cummins has the advantage because it develops HP at a lower RPM.

 

[klenger]

Didn't mean to sould like I was disagreeing, 'cause I wasn't. Your theory seems valid.

 

[fbaurley]

The new emissions requirements are what prompted me to buy my 305 , 555 in October (along with the incentives offered). I ddint want to take the chance on EGR. When i found out there was no EGR and more torque and HP I was a little disappointed. But then when I found out the 04. 5s have an electronic wastegate, and a supposed extra injection event to add fuel in exhaust to help the DOC burn, I was glad I ordered when I did. For my personal needs, ill take the simplicity. Not that the new ones will have problems, I doubt they will, but down the raod ill probably modify my rig, a for that the simplier is better. If i was looking for a new truck id have no reservation on buying a 600, but for my it was a timing factor to buy the 555.

 

[Big_Daddy_T]

This is coming from a recovering bomber. I went big and loved it. I had my fun and now have decided to stay in the 600lb ft range. For longevity of all parts involved. So the 600 really catches my attention as a truck that I would leave bone stock and still be happy as a lark without ever thinking twice about my warranty. I cant afford to be my own warranty station anymore. Im thinkin about trading in my guzzler pretty soon as I would see a 200 dollar a month fuel savings.

P. S. I think im getting less than 10 mpg now. Oh gee. Im filled with glee. This trucks a bum.

 

[DLeno]

I've been anxious to hear what the fuel economy of the '600 is. Since the changes appear to be motivated towards reducing NOx, there's been a few things of theoretical interest that got me wondering:



1. From thermodynamics theory, I note that the efficiency of a heat engine is reduced with a reduction in temperature of the high-temp resevoir. Since the reduction in combustion temps is a consequence of the desire for reduced NOx, this would suggest a lower efficiency engine. I wonder if this is true and if so by how much.



2. The work on the cooling system to improve cooling efficiency also implies to me that there has been an efficiency decrease. As before I want to know if this is true and if so, by how much.



comments anyone?

 

[DLeno]

just raising this one to the top again as a contribution to the 04. 5 fuel economy discussion. see my previous theoretical musings above...

 

[JWerkheiser]

I would have been perfectly happy with my '03 had Dodge attempted to fix the loss of throttle control problem it had. They decided to call it 'normal'. So, I was forced into the 04. 5 with the 600 before I ended up killing someone. Other than the mileage issue (and we'll see how it ends up after break in and/or Dodge/Cummins address) I really really like this new truck. Much more power now in lower rpms than the '03 had. And I like the sound of the engine better. So, I don't think anyone is better off with an '03/'04, or an '04. 5. Both great motors in a great truck. I think down the road, enhancements for the '04. 5 and newer will be easier to find than for the '03/'04s simply because of the limited production of the ISB305. Not that it matters much. I have no plans to modify.

 

[ceastmen]

As an 04. 5 owner for 1700 mi now I'd say this truck has the following good and bad points:



Good:

1. Hanldes like it's on rails! (UNBELIEVABLE HANDLING! Way better than 2nd gens... )

2. Quiet and smooth, except for a shudder on takeoff which is being evaluated by DC at the moment... more to come

3. Very good ride for a 3/4 ton truck

4. Fit and finish are very good

5. Comfortable

5. Brakes are responsive and proportional to user input



Bad:

1. Fuel Economy - so far, being nice, i'm averaging 15. 5 MPG empty (I know - it's not broke in yet but still, how much can you expect it to improve? 3-4 MPG? No way!) I think 600 owners are stuck with less fuel economy than the 305/555 owners. Looking at it form the outside 15 MPG for a huge heavy truck is good, but not as good as previous years.



2. I drove my Bro's 2nd gen with a EZ fuel box on level 2 (his is the 6-speed and mine is the 48re auto) and his would KILL mine. Not to say the 600 is slow, not by a long shot, but a simple mod on an older truck will kick mine to the curb.



I wouldn't trade the 04. 5 for an older model, maybe an 04 305/555 with the 48re; however, if the mileage improves, I wouldn't trade it for anything else.

 

[DLeno]

Originally posted by JWerkheiser

I would have been perfectly happy with my '03 had Dodge attempted to fix the loss of throttle control problem it had. They decided to call it 'normal'.

woa, guess I wasn't listening when this surfaced. whats the throttle control problem on the 03? I thought my 02 was too jumpy and REALLY like the smoothness of my early 04 (no change to the Engine from 03).

 

[JWerkheiser]

The throttle control problem was basically at launch, the computer would fuel to governor speed (3500rpm) with as little as 1% throttle applied. Only did this if you touched the throttle after you let the clutch out and the engine started to recover RPMs on its own.

 

[CAgnoli]

I read several threads on MPG in these very forum's for two weeks prior to purchasing my "600". I too believe that Dodge/Cummins will work through the ecomony issue. (EPA or Not, you can't sell trucks for 40k+ and expect the buyer to "accept" subpar mileage. )



My dealer insisted that the truck would get 18+ on the highway AFTER 10,000 miles.



I've put just over 2100 miles on my 3500 4x4 QC "600" and my last tank was 17. 8mpg. Admittedly, this was with 80% highway driving, with the cruz set to 65, but it shows an improvement. I drove the truck on the second tank at 70 to 75 with a few 90+ passes, and hand calculated the mileage to 15. 6.



I am planning on leaving the Cat on my toy, and simply upgrading the intake, and covering the bed with a hard tounnue or something of that nature.



With that being said, IF the truck isn't getting 19MPG average on the road empty after 15,000 miles... ... . well..... I'm going to "engage" the dealer. After all, I too purchased this truck with the knowledge that my best friend had a 2001 HO with a box that was getting 22 on the open road empty.



I drive 1000 miles a week, so I'll keep you guys posted on the mileage improvements whenever feasible.



Otherwise, I really like the truck. It definately sounds like a diesel, just not a rattely shaken and abused powerstroke