On 19 Sep 2015 14:29:47 -0400, (Scott Dorsey) wrote:

wrote:

Then how do you explain the FACT that todays engines -
1)produce higher spedific output than engines in the past
2) Consume fewer gallons of gas per unit distance travelled
AND
3) produce lower exhaut emissions

-than the engines of only a few years back - muchless the
"uncontrolled" engines of the 50s and 60s, and the early emission
engines of the 70s and 80s?

This is almost entirely the result of fuel injection combined with
accurate feedback control. Feedback control makes a huge improvement
in the efficiency of the engine and that means both lower emissions
and more power.

And, it's true that it took the emission control regulations to force
the car manufacturers to start thinking out of the box at new ideas to
try and improve efficiency back in the seventies. Had it not been for
the emission control regulations, we might never have got the engine
improvements that make engines so much more efficiency today.

BUT, it's true that many of the other tricks used to get emissions
numbers down have been at the expense of performance, and many of them
have been just plain attempts to game the system.

There is a very longstanding tradition of gaming the system, dating back
to air pumps back in the seventies which did in fact improve the efficiency
of early catalytic converters, but mostly just diluted the exhaust so that
the concentration of emissions was reduced. The actual amount of emission
was the same, but the numbers recorded at the smog station were lower.

The improvement in emissions was at least an order of magnitude more
than the "dilution" would have produced. This was in the days before
"storage" catalysts that can store oxygen (part of the reason mixtures
MUST oscillate around stoich - go rich, then lean, then rich) Air
needed to be added in order for the oxidizing catalist to function
effectively.

This current attempt on VW's part is not something new in isolation, this
is part of a tradition going back forty years now. It shouldn't surprise
anyone, and it's certainly not anything specific to VW.

VW will just have to step up to the plate and spend in retrofits what
they should have spent in initial design and production - plus.

Odds are that instead they will take the route of just leaving the
controller in "low emissions" mode all the time, which probably will
affect performance. Part of how that will work out will depend on what
they were actually doing to bring the numbers down, and we don't know that
without actually measuring it or looking at the controller source.
--scott

"The improvement in emissions was at least an order of magnitude more
than the "dilution" would have produced. This was in the days before
"storage" catalysts that can store oxygen (part of the reason mixtures
MUST oscillate around stoich - go rich, then lean, then rich) Air
needed to be added in order for the oxidizing catalist to function
effectively. "

Wow, even I wasn't aware of that. I was aware that actually a car can be made to run better without a cat, to the point where the emissions would be about the same, that something has to keep that cat lit, but not why they did that. I thought it was just like a servo hunting and or some reason they couldn't get rid of it. But i have been out of the loop for some years now.

The bottom line is the only way to test a cat is by O2 content. They cnnot check by emissions because in a properly running car, and I mean REALLY properly, there are no emissions to convert.

The cat does not help cars the really run right, it helps cars with cumulative inaccuracies in the build. Normal production tolerances do not have to be as tight. Hell, they don't even lap the valves in anymore. That'll save you a few manhours on something with 32 valves eh ?

I still maintain that no regulation has passed without the approval of the automakers. They have lobbyists. The regs give them an excuse for highway robbery. Literally. It also makes starting a new car company much harder, thus keeping down competition. No more Tuckers !