California Emissions

[Oldtimer]

Just discovered my std transmission truck is equipped with California emissions. Whoa! Not required here in NH, but provided by delivering dealer. My question for you well informed folks: what differences has GM made to differentiate CA from Federal Standard? What disadvantages... lower milage? Less power? Have already learned I cannot install std Pac Brake. Tech rep says I've got exhaust gas recirculation. Ye gads, what else to reduce diesel volumetric efficiency?

[oyazi]

A CA truck delivered to NH? UPS must have had a hand in it :D :D

[Oldtimer]

Well OZAZI, I wish I could blame UPS. But I researched dealers searching for a manual transmission and the only one on the East Coast was in MA. Unfortunately what I didn't know, was that vehicles delivered to MA dealers are apparently equipped with CA emissions! So it's my fault and I now got a vehicle encumbered with stuff that's good for the EPA by bad for the driver. I've been told to sell it and get a 2001 model Duramax which doesn't have EGR and a Cat.

[56Nomad]

Oldtimer,

Before we purchased our truck, this was a major concern so I wrote
e-mails to some of the the mechanical engineers both at engineering
universities as well as individual companies who manufacture cataylic
converters for diesel engine. Most replied that the 'California engine"
has no fuel economy penalty. Several, said that theortically there
might be a slight loss of fuel economy. One engineer went out of his
way to contact GM and GM claims to have tested fuel economy..
no loss (what do you expect?)

After reviewing many of the posts about mileage on this forum, the
CA owners don't seem to have any difference in fuel economy than
owners with out this CA option.

Here is the summary of the changes that were done in 2002.... the
2001 CA trucks did not have these options.
California was the only state that required this
option in the 2002 models...
Just one more reason why the costs keep going up :mad:

SUMMARY OF NEW OR CHANGED FEATURES FOR 2002

Exhaust Gas Recirculation (EGR) for California
Revised Cylinder Heads for California
Catalytic Converter for California
Accessory Drive Belt Tensioner Relocated
Software for Engine Control Module (PCM)

FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES

EXHAUST GAS RECIRCULATION (EGR) FOR CALIFORNIA
To meet new Low Emissions Vehicle (LEV) standards for
medium-duty vehicles, 6.6L LB7s built for registration in
California will be equipped with EGR. The system
features a unique cooling process that increases its
effectiveness. Hardware required includes: plumbing that
carries some exhaust gas from the turbocharger outlet to
the intake ports; an EGR control valve; an intake throttle
plate that creates vacuum to induce the flow of exhaust gas
back into the combustion chambers; and a
stainless steel cooling element. The cooling element bolts
to the right side of the engine block, inside the cylinder
head, with jackets fed by engine coolant.
Returned exhaust gas passes through a spiraled passage in
the element, and the temperature of the gas is lowered
before it returns to the combustion process. The
EGR valve and intake throttle are managed by the PCM.

REVISED CYLINDER HEADS FOR CALIFORNIA
Heads for California 6.6L LB7s have a new, slightly
different casting which modifies the intake ports to
accommodate EGR. The ports are repositioned relative to the
combustion chamber, entering the chamber at a slightly
greater angle and increasing the swirl or mixing effect
inside the chamber. More swirl is necessary to
thoroughly blend returned exhaust gas with the air-fuel
mixture.

CATALYTIC CONVERTER FOR CALIFORNIA
California 6.6L LB7s will be equipped with a catalytic
converter supplied by Delphi. This high-capacity converter
measures 309 cubic inches in volume. LB7s built
for registration outside of California will not have the
catalytic converter.

I would not worry about it at this point! Enjoy
your wondeful truck.

Best to you

[ 02-12-2003: Message edited by: 56Nomad ]</p>

[Oldtimer]

56Nomad,

Thanks for the thoughtful detailed response and advice. I offer one footnote. I solicited information from the truck supervisor of NH's largest GM dealership. He informed me that all Duramax diesels vary widely in power, fueling, and timing -- few really produce the torque and horsepower advertised. He asserted 3500 models produce more horsepower/torque than any of the 2500 models. All are currently detuned to enhance longevity and reduce dealer warrantee costs. The key lies in the PCM program for each truck.

What is advertised is merely what the engine is capable of, not what any specific truck is enabled to produce in the way of power or efficiency. He asserted that this explains the widely varying reports of milage reported on the Diesel Page and elsewhere.

Caveat emptor

[pinehill]

Oldtimer,

Welcome to the group!

You may not have had the opportunity to read all the posts which have appeared here containing the results of dyno testing of stock Duramax engines. These results consistently show rear wheel horsepower at 240-258, with most centered at 245. This corresponds to an approximate 18% drivetrain loss (Allison). Torque figures, of course, have been commensurate, since the dyno directly measures torque.

Yes, in stock form the engine is only moderately tuned. You will find here that there are aftermarket systems which will provide much more power at moderate costs and with very little effort in installation.

None of the members here who are close to engine and truck production processes have ever noted a special engine selection or tuning for 3500 vs 2500 trucks. This dealership truck supervisor, unfortunately, appears to be no more knowledgable than most personnel at dealerships.

[ 02-12-2003: Message edited by: pinehill ]

[ 02-12-2003: Message edited by: pinehill ]</p>

[56Nomad]

At the 2002 Rendezvous, they ran 8 Duramax
trucks on the BD dyno. Terry Pittman, who
has CA emissions/with a Cat ran at 247 HP with all stock equipment.

He out-performed some of the trucks without
CA emissions.............

[Tsckey]

I wouldn't put much stock in someone's representations that the factory deliberately detunes the engines below advertised figures. Certainly there will be variations, but were the General to engage in that practice it would be exposed to MAJOR liability for deceptive marketing. It's been down that road before with generic engines. I doubt it would do it with our trucks in these very high profile power wars. I have no problem accepting that GM left a large margin for relatively easy upgrades to keep apace with Ford and Dodge offerings. The Dmax is a very sophisticated engine, probably doesn't begin to break a sweat in stock tune.

As far as California emissions choking off the power and mileage, I guess I must have whatever the opposite of a lemon is, a pearl or something. I get terrific mileage, the thing has gobs of power (without a box) and runs like a watch.

TC