For cars in states with more stringent laws like California and Maryland. VW may still need to do more to keep their cars on the road there.
Nevada, for all these decades cars have been subjected annually to emissions testing to ever-more-stringent standards in numerous states, including NH. Diesels were not, and ran around for eight to 16 hours every day blowing clouds of soot too thick to see through. Diesel cars were also exempt.
I should add that particulate filters do not trap NOx, CO, and many of the unburned HCs that diesels push out (remember that oil is a hydrocarbon).
Diesels are dirty. Even modern diesels cannot meet the same emissions levels that cars are subjected to, and trucks push out far, far higher volumes for far, far more hours per week than any car⊠except (on the hours) perhaps a NYC taxi.
Diesels got a free ride for years.
Annual emissions testing is a local responsibility unrelated to the manufactures requirements. To say that diesels have received a free pass for decades ignores the emission requirements and advancements made with diesel engines during the last 25 years. If diesel engines had no emission standards until recently this Volkswagen topic would not exist.
NH didnât have emission testing until just a few years ago. MTNBike makes a good point. Diesels still canât meet the same standard that gas cars must comply to.
Other, more populated states have regulated diesel vehicles and fuel for a long time. The first low sulphur diesel fuel was mandated in 1993. During the first decade of this century, California introduced on and off road diesel pollution regulations almost every year. They even introduced a program to retrofit older diesel trucks to improve air quality.
Actually, whether you had to get emissions testing in NH depended on what county you lived in. I got it every year for decades until I moved to a county that was exempt. Donât know about Mikeâs hometown.
As to emissions testing not being related to manufacturersâ requirements, thatâs incorrect. Emissions are tested TO the manufacturer-mandated output standards for the model year to which the car was manufactured. Now, in NH, itâs an OBDII download, but everything required of the manufacturer must be in order without any fault codes. Older cars only have to meet the standards required at the time of their manufacture. Cars older than 25 (I think) years are exempt⊠I think.
Emissions testing requirements are DIRECTLY tied to the requirements at the time of manufacture.
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Forget about the elephant in the room?
In the state of Nevada there is no correlation between manufactures requirements and local testing. New vehicles must meet a standard that is measured as total exhaust volume/grams per mile. There is no economical way to perform this in multiple locations in urban areas. Local testing measures percentage and parts per million in the exhaust stream and/or opacity for diesel engines.
The tailpipe limits in Nevada are 1.2% for CO and 220 PPM for HC from 1981 to 1995 with no change in respect to tightening manufacture requirements, this is more than ten times the output of a normal operating engine. I donât see any tailpipe testing requirements for New Hampshire, I donât see how your testing is âDIRECTLY tied to the requirements at the time of manufacture.â
As for OBDII testing, if there is no tailpipe testing how can this match the manufactures standards? Manufactures have strict output limits to adhere to. Once the vehicles monitors have passed there wonât be a failure unless the vehicle exceeds 150% of the manufactures limits.
If the engine is working properly then the engine not putting out too much emissions. If itâs NOT working properly then there will be an OBD-II fault. Itâs pretty simple.
The other point about OBDII downloads is that the system also monitors evaporative emissions, which a tailpipe test has no way of measuring.
No test is perfect. But I think the bigger problem is the current standards result in countless OBDII codes that often cannot be diagnosed and corrected. States that use this system have a minimum amount where if the motorist spends it he/she gets a âpassâ, because the current problems with false positives have proven to be so difficult to surmount. EVAP requirements required of the manufacturer, to which the OBDII system monitors, are unrealistic IMHO.
My state has 2 counties requiring annual emission tests. One is the most populous and the other is in a hole where smog lingers. I donât live in either one. Many people just register their vehicles in a test free county.
Smog out west is strange to me. I was in Logan, UT this winter, and they had more than one smog alert. This was the middle of the winter, in a small university town with no heavy industry. Odd, just odd.
Well, there are âtemperature inversionsâ which trap air close to the ground plus pine trees which put out organics.
And there are fireplaces and wood stoves - we were driving through northern California on vacation, a winter evening, and there were layers of smoke in the woods from the fires in peopleâs houses, even though there was no town. Must have been no wind, either.
I think I heard there was an inversion and that it is common in a valley like Logan. I would believe a large city like LA, but a small town is surprising, no matter the reason. Logan is a beautiful place, BTW.
Any time you have a valley surrounded by mountains, you have the setup for a temperature inversion that traps smog, both man made and natural, in that valley. Inversions happen in a lot of places, usually after sunset. You can feel the air suddenly getting warm as you ride a motorcycle up the hills and then getting chilly again as you go back down into a valley. When someone burns leaves, you can see the smoke rise until it hits the inversion layer, and then it just spreads sideways without rising farther.
That inversion layer is also the reason you can hear fishermen in the middle of a huge lake talking to each other as if they were only a hundred feet away, even though they are nearly a mile away from you. The sound bounces off the inversion layer and gets reflected back to the ground, sort of like radio skip. The sound effectively gets trapped in the cold air layer close to the ground.
There were days when we could hear the high school band play on the football field late at night even though we were miles away from the football stadium.