On Saturday, September 26, 2015 at 2:43:01 PM UTC-4, Ashton Crusher wrote:
I didn't say it was difficult, just that it's easier to run a test
on the dyno. And it's a controlled repeatable environment. Driving
on the highway 500 miles today could be under different conditions
than tomorrow, that you have no control over, ie traffic backed up,
slower speeds, more accelerating, de-accelerating, etc.
On Sat, 26 Sep 2015 12:00:06 -0700 (PDT), trader_4
Which is exactly the situation you WANT to find out about... How does
the system, which seems to be working in the "lab" actually work in
the real world. Sure there's more variability, so what. The point of
emissions controls isn't to keep the soot off the walls of the "lab"
it's to keep the soot out of the atmosphere out in the real world.
On Saturday, September 26, 2015 at 9:06:42 PM UTC-4, Ashton Crusher wrote:
I think we're getting off track here. The post I replied to, I
believe it was about VW having sent the cars to some outside lab
to be tested and they passed. Someone questioned how that could
be. I simply said probably because that outside lab tested it
the same way, on the dyno. Since presumably VW didn't want to
"find out about it", it would seem highly likely that they made
sure they understood how that lab was going to do the test.
I would have to disagree. The point of the emissions test is to
pass whatever the standards are, the test methods, as defined by
EPA. If the EPA says running it on the dyno it has to put out
no more than X, Y, Z, then that's what counts. They shouldn't
be cheating on the test, but designing it to meet the EPA reqts
and the EPA required testes is what counts.
The scam was discovered by actual road tests. It is also possible the
test units were rigged when sent for testing. If it was dyno, it would
have passed. I'm sure there will be a lot of road testing done to
verify what others are doing.
Was the software really all that "sophisticated"?
The NY Times said it was "sophisticated".
I think it was just brazen.
Apparently cheating is rather common.
Volkswagen Test Rigging Follows a Long Auto Industry Pattern
By DANNY HAKIM and HIROKO TABUCHISEPT. 23, 2015
YOu're overthinking it. It's about driveability
If the rear wheels ain't turning, you should turn on the emission
controls. When the car is stopped in traffic, might as well make it
clean. Performance isn't an issue when stopped.
I'd have taken it a step further and made it clean whenever driveability
isn't compromised...like when not accelerating at a rate faster than
you could do with the emission controls functioning.
Probably would never have been detected.
On Monday, October 5, 2015 at 3:06:21 AM UTC-4, mike wrote:
Actually, we're not sure what the real issues were. There is speculation
that it's MPG and performance, which if true would make what you say true.
It's also possible that some emission components are adversely effected,
don't last as long, will fail if used continuously, etc. The last thing
I saw, VW is saying that it was done because they could not meet both
emissions and cost constraints. Which might play into the scenario that
if the emissions controls are on continuously, or used enough, something
I'm not sure they even read levels. They do check to make sure the
emission ready monitors have been set, which indicates that if the
computer has been cleared, then the car has been driven long enough
to reset them. Other than that, they are probably relying on the
computer not having any emissions failure codes set. The cars don't
have the instrumentation to measure all or maybe even any of the
actual emission components directly. Whatever they measure, it's
obviously even easier to cheat when only the OBD is used. The computer
just says everything is OK all the time.
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