I'm having a problem with my local Dodge dealer. It's Tucson Dodge if anyone
is interested. Called them and asked if there was a TSB on my truck about
the fuel mileage. They asked for the VIN number and I gave it to them. They
said, no TSB's on that truck. People keep telling me there is. So I called
again, same answer. Someone on the MML emailed me a link to
this:http://dodgeram.info/tsb/2004/18-037-04.htm so I called the dealer back
and asked why I was not told about this and had to do my own investigating
to find it. They gave me the run around and I'm a tad upset about it. They
actually told my this procedure may reduce the fuel mileage. How can I find
out what the truth is and how can narrow down my searches to find TSB's for
And, is this worth doing? http://dodgeram.info/tsb/2004/18-004-04.htm
This TSB you reference will do nothing to help your fuel economy so the
dealer wasn't giving you the run around. It addresses exactly what it says
As a disinterested third party, I would be happy to check for applicable
TSB's and advise you accordingly. Just email me with your VIN and I will
check for you .
What kind of fuel economy are you experiencing? City? Highway?
Laden/Unladen? Any mods to the truck? Different tire size than OEM?
Driving style? Tire pressures? All of these can (and do!) impact your fuel
Over the years, the biggest factor I've found in poor fuel economy is the
nut holding the steering wheel.
Chryco Service Manager
Sorry, but here is what the TSB says: (
a.. Improved Fuel Economy - A new ECM calibration has been developed which
should provide customers an average fuel economy improvement of
approximately 1 M.P.G.
a.. Reduces white exhaust smoke on cold start at temperatures below 50 deg.
F (10 deg. C).
a.. Improves accuracy of the fuel economy calculation in the overhead
Note the first line.
My mileage is very good at low speeds. If I drive fast, like 75, it goes way
down. Truck is completely stock, has 3.73 gears and a six speed manual. Here
is why I think something is nuts. Pulled a trailer and race car to Northwest
Phoenix, and drove the truck back completely empty. Kept between 60 and 65
on the way up and about 75 on the way back. The trailer and race car have to
weigh over 5,000 pounds. Got better mileage on the way up. And on the way
up, I took the wrong exit and got stuck in stop and go traffic for about 45
minutes. Makes no sense to me.
Ooops! Sorry! The TSB referred to in the body of your text is a different
TSB than the one you provided a link to and I incorrectly asssumed they were
one and the same.
Define very good
If I drive fast, like 75, it goes way
Define way down
Truck is completely stock, has 3.73 gears and a six speed manual. Here
Define better mileage
And on the way
Al, I got your email with the VIN and will check TSB's for you however if
you are concerned about fuel economy as a result of this one trip, then what
you have is really no more than anecdotal evidence. In order to truly check
fuel economy, it must be done over several fill-ups removing the variables.
For example, fuel variability can account for a 1-2 mpg difference. This
could be the difference between winter blend and summer blend diesel.
Also, driving conditions can play a big role. When towing my RV in flat
level conditions, I can usually get ~13mpg at ~70mpg. On the other hand,
when towing in hilly or mountainous conditions, the fuel economy drops to
~9.5 mpg. This can occur (and frequently does!) on one trip. On one RV
trip in recent memory, the presence of a stiff head wind dropped my fuel
economy down by ~ 2mpg.
Here is more info. Bought the truck new from Royal Gate Dodge in St. Louis.
It came with a full tank of fuel. Filled it myself and it was really full:)
That first tank gave me an honest 19.6 MPG running around in St. Louis and
driving slow, around 55 MPH to Chicago and back. Then I drove it back to
Tucson. My mileage went to around 13.5 driving a steady 75. I'm going to go
through all my fuel receipts and see how it's really doing. My last two
tanks was mostly city driving and I got right at 19 when I averaged them
On the way to and from Phoenix in the example I listed I was going by the
overhead MPG indicator. It might not be accurate but since it was all in
the same day the figures should be at least an indication of the difference.
I reset it, drove up there, reset it and drove back. Little over 125 miles
each way, was about 3 MPG better on the way up.
The seat belt chime has also gone nuts and now the "key in" chime is
intermittently nuts too. Hope this is not indicative of a more serious
problem. The truck is going in for the chime problem later this week.
Thanks for the help.
The rub is my friends, two of them, have 02's and they are both getting over
20 on the highway. One is automatic the other is stick. Or they both are
Nope, they're not. You need to understand that you have a different engine
than they do. Yes, they're very similar, but with completely different fuel
systems. Is it so unreasonable to expect a drop in fuel economy when
bumping the HP from 235 to 325? Or the torque from 460 to 600?
It's a known fact that the 3rd gen engines are less fuel-efficient than
previous 24V engines. And the '04.5 engines get worse mileage than '03 or
'04 engines. This is all due to increased emissions standards, and in the
case of the '04.5, is directly attributable to the 3rd injection event.
It's also a known fact that the 2nd gen trucks are more aerodynamically
efficient than the 3rd gen trucks, which also accounts for the drop in fuel
economy. Since the trucks that have the Cummins as an option aren't subject
to CAFE regulations, DC isn't as motivated to push their engine supplier for
fuel efficiency. Therefore, Cummins first priority on their engines is
meeting emissions requirements - fuel economy is a secondary concern.
It's simply the way it is, and doesn't mean anything is wrong with your
Aha! Now we are getting to the crux of the matter :^).
As Tom L. correctly pointed out, your 2004.5 will never get the fuel economy
of a 2002. The power output difference between the two engines is just too
great. That power output diff has to come from somewhere and that somewhere
is fuel economy. The emissions regs play a large role too.
In an earlier post, you indicated around 19 mpg around town in StL... that
sounds about right. My '03 HO with 3.73 gets around 19 mpg with a
combination city/highway driving.
Send me your correct VIN and I will double check the TSB's for you tho' just
to be sure.
Wind resistance........... next to high speed this will kill your
millage. Once had a slide in camper I hauled with my Cummins. Would get
18-19 all day long driving around town but as soon as I hit the
freeway the mileage dropped to 13-14.
Mike might can verify this, and while the TSB in the link above
doesn't say it, ISTR that there was some kind of temperature
restriction for the idle speed function to work too. IOW, you can't
set the idle up if the outside temp is above xx degrees similar to the
operation of the grid heaters?
Your mileage is correct. If you don't want 14 MPG, don't drive 75. The
optimum speed for your truck is 55. I have 4.10s and my optimum is 45-50.
These trucks are not aerodynamic. Don't drive fast if you want to conserve
I don't know. I have an early '04. You have a late '04 and you have triple
event injection and I have a double. If you are smoking a lot, probably yes,
if not then no. I would ask Tom Lawrence, he will know.
Actually Mike will probably know better once he looks at the specifics.
Off-hand, I would say the flash won't hurt your mileage, and could very well
improve it slightly (don't get your hopes up - we're talking less than
2MPG). Many people with '04.5's have reported slightly better fuel economy
with this particular flash. As I have an '03, I tend to not read as much
about the "triple-squirters", since it's not my problem :)
If it were my truck, I'd ask very nicely of the service manager to load this
flash, and perhaps even embellish a little on the amount of "white smoke on
startup" - as that's what the main purpose of the TSB was. Remember - it's
just a TSB - it doesn't mean you're automatically entitled to have the
service dept. do whatever it says (as you would be if it were a recall).
From the first 12V 6BT's, through the last of the VP44-injected 24V ISB's,
there has always been a single injection event, hydraulically-actuated (pump
puts high pressure on the fuel line, overcoming the spring in the injector,
and the injector "pops off", spraying fuel through the nozzle).
With the advent of electrically-actuated injectors, it became possible to
have multiple injection events per combustion cycle. Starting with the HPCR
engine in '03, there was a 'pilot' injection event, which squirted a
miniscule amount of fuel to begin the combustion process, followed by the
main injection event, which delivered a much greater (by comparison) amount
of fuel. It's this pilot injection that had the most dramatic effect on
quieting the engine. Instead of all the fuel arriving (essentially) at the
same time and exploding, a much smaller "explosion" happens during the pilot
injection. Now when the main injection event occurs, it's more of a "burn"
rather than a "bang". That reduced the classic "clatter" noise of the
diesel significantly, provided more power, and is probably a little kinder
to the engine, as well.
Starting in '04.5, Cummins added a "post-injection" event - which has
something to do with cleaning up the emissions (yeah - go figure - they make
it cleaner by spraying more diesel), and the way things interact with the
catalytic converter, etc. etc. I don't understand it, and frankly, I don't
want to. There's great interest in a programmer that can turn off this
third event, as it does nothing for power production. There may be a
solution coming in the next several weeks out of Italy... time will tell.
At any rate, there's your "triple squirt" - pilot injection, main injection,
and post injection.
ah ok i was familar with the mechanical injectors. and the pre injection bit
to quieten the engine. but was out of the dodge shop aparrently before word
of a 3rd squirt was passed down my way anyways. and had me puzzling as to
why there would be. thanks for the info.
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