Engine/Transmission (1994 - 1998) Why?

[SteveAnsley]

Just currious.

Why is the 12 valve without the computer controlled pump generally known to get better fuel mileage than the 24 valve w/ the computer control?



For the most part, the automotive industry has shown that the incorporation of computer control seems to been able to improve mileage.



Don't misunderstand, I love my 12V'r and the fact that it does get great mileage and I'm kinda of old school anyway regarding the mechanical pump.



Just currious.

Thanks,

Steve

 

[Bill Lins]

In gas engines, computers fine-tune the fuel-air mixture, getting as close to "stoich", or optimum.



In the 24v engines, it seems the computer tunes the engine for minimal emissions, not mileage.



Just my opinion, of course. ;-)

 

[JFaughn]

To add to that , I see a lot of shows on speed channel and they are putting a lot of these mods on the 3 diesels trucks and getting more HPs and MPGs still passing emissions , what the hay ?

 

[biggy238]

I've not ever seen results on a current engine's emmissions after being tuned, but it's not like they had much to deal with before from the current laws. I've heard of some high horsepower 12vtrucks running "clean" during a smog check. . 2007 will be a whole new ballgame though.

 

[Vaughn MacKenzie]

Of course the emissions checks at the DMV stations are only a basic opacity test, and something that passes there could still have NOx & particulate emissions many times higher than the EPA standards.



The 12v probably gets better mileage based on more advanced timing, although the timing on a 12v is fixed (stays at 15* or whatever you set it at at any RPM) whereas the electronic engines it's dynamic (changes with RPM & load).



In all the MPG threads I've read over the years I don't think the 12v gets that much better mileage than the 24v given equal trucks and work load. My '96 gets decent mileage unloaded, but under towing conditions MPG is quite a bit worse than my last two trucks, although they were 4x2 ('01 and '03).

 

[Katmandu]

I've not ever seen results on a current engine's emmissions after being tuned, but it's not like they had much to deal with before from the current laws. I've heard of some high horsepower 12vtrucks running "clean" during a smog check. . 2007 will be a whole new ballgame though.

What's going to be different for Emissions in 2007 ??

 

[Mundgyver]

Here is something to think about. Chipped Diesel Engine Technology is where the gassers were about 15 years ago in their development cycle. If you watch the technology over the next 5 to 8 years and keep track of the changes, I think you will be amazed at what the differences will be when you look back.

 

[Champane Flight]

Latest

Just talking to a couple of owner operators (truck drivers), they are putting orders in now, before 07 regs for new trucks. They are getting bad reports on 2007 engines, no power, and unreliable. We will see. .

 

[Forrest]

In gas engines, computers fine-tune the fuel-air mixture, getting as close to "stoich", or optimum.



In the 24v engines, it seems the computer tunes the engine for minimal emissions, not mileage.



Just my opinion, of course. ;-)

Correct, I know one 24v fellow BOMBER that experimented a little with his Comp, which is the adjustable box, & found better mileage on the 2/1 setting. Timing change might be involved there.

 

[WyattEarp]

I have both the 12V and 24V now, and to be honest i can't say anything against either, the fuel mileage with the 5speed 12V is better, but if you think the 12V engine is a few pounds lighter not sure if that matters or not...

As for the emmissions testing. . they can blow that out their wahzoo's, the diesel engine no matter what yr model will always burn cleaner and put far less pollution in the air than any gasser every will... Okay so one smokes, i would rather follow a smoke belching diesel any day of the week than follow a gasser thats burning a qt of oil every 50 miles... Of course i love the smell of diesel... who knows where all this will go, i know one thing, both my dodges will continue to run no matter what emmissions they come up with...

 

[Dieselnerd]

Having owned a '96 and a '05 both with 4:10 axles, both towing the same 13K trailer, I can report an interesting situation which has also been reported by others. Towing, my '05 gets 2 mpg more than my '96 did. Solo, my '05 gets about 2 mpg less than my '96 did. My theory is that under high load conditions the computer manages the fuel more efficiently. The '96 would put out some smoke when towing and the '05 doesn't.