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.

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

--
"C'est un Nagra. C'est suisse, et tres, tres precis."