Hi Paul.  "In denial on the diesel..."  ??? Please explain.

dave
mailto:dave@arb.net
http://arb.net

They still are not convinced it causes cancer. When you accelerate a diesel engine
the first thing that happens is a much richer mixture. This causes smoke or
cancer causing particulates. If it does not go rich it does not accelerate.
The air intake is already wide open. It is always wide open.
Diesel's control the speed by controlling the amount of fuel injected not the
amount of air. That is how you make a diesel engine accelerate. When you see a diesel
truck smoke that is what is happening. The driver just floored the accelerator
pedal.

With a gas engine the first thing that happens is it wants go lean but the
computer can keep up and keep the mixture in the proper range. Gas engines
speed is controlled by throttling the air. This is a fundamental difference
between the gas engine and the diesel engine. Several devices have been developed
to mitigate this diesel particulate problem. What is universal used now on
European car diesel engines is this variable vane turbo charger. This causes
the turbo to speed up faster attempting to supply enough additional instantaneous
air to keep up with the richer mixture so to speak. Another device is an electric
motor boosted turbo charger as used on the RX8 hydrogen powered car.

Paul Lamar

I understand now.. There are several ways that are currently in production to
deal with this - #1 is CRD - basically electronic fuel inject for a diesel. The
second is a catalyst. Most of that smoke is hydrocarbon. The carcinogens are mostly carbon
particles... And these are handled by a post catalyst filter. The Liberty diesel
that goes on sale here in November will meet the new emission standards and get
great economy. If it were a convertible, I'd buy one...
-dave

 
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