Topic: Emissions of Newer Cars vs Older Cars

[X-Traction]

I read that cars newer than around 1992 are something like 16 times "cleaner" than cars older than that.  I'm wondering if this is true, or if it is a misleading generalization.

Our 1990 Dodge Spirit just went through emissions testing.  Here's the results:

.................Max Allowed....Vehicle Score....Avg. Pass Score

Driving Test

HC ppm........... 90................. 19................. 42
CO2.............. .76................. .13................ .19
NOx ppm........ 1117............... 50................. 152

Idle Test

HC ppm.......... 102................. 4................... 15
CO2%............ 0.75................ 0.0................. 0.02

Are newer cars really 16 times less polluting than this?

Here's the Canadian Government source, which says:
"Did you know that on average, older vehicles emit 19 times more harmful pollutants than a newer vehicle of model year 2004 or later?"
http://www.ec.gc.ca/education/default.asp?lang=En&n=343C9FDB-1

[X-Traction]

I've partially answered my own question.  BC's Air Care has a calculator to compare CO2 emissions.  It shows a Spirit equipped like ours generates about the same amount of CO2 as a new Ford Taurus or Dodge Grand Caravan.

The calculator leaves out two important pieces of information. One is that it rates CO2 instead of the emissions used in the actual Air Care test.  Odd. 

The other problem is that it doesn't say if the scores displayed are the maximum allowable or the average results for the cars.  As for our car, obviously it runs cleaner than whatever set of cars are used to calculate the average stated on the test form.  So if the average is used in the calculator, then our car is really doing much better than the 2010 Taurus and Caravan.

Whatever the answers to that, it's very clear that our car does not spew out 16 times as much pollution as newer cars.  So that means there is some very serious misinformation being spread around by government agencies etc. about old cars being "dirty".  And it also means these "cash for clunkers" programs may be based on false information.

I'd readily agree older cars are more likely to pollute more, but probably it would be far more cost effective and environmentally sensible to even subsidize people to get their older cars running in top shape rather than send them to the crusher and build new ones to be sold to people with thousands of dollars in rebates.  Of course, our economic models favor the latter.

[rrocket]

I've partially answered my own question.  BC's Air Care has a calculator to compare CO2 emissions.  It shows a Spirit equipped like ours generates about the same amount of CO2 as a new Ford Taurus or Dodge Grand Caravan.

The calculator leaves out two important pieces of information. One is that it rates CO2 instead of the emissions used in the actual Air Care test.  Odd. 

The other problem is that it doesn't say if the scores displayed are the maximum allowable or the average results for the cars.  As for our car, obviously it runs cleaner than whatever set of cars are used to calculate the average stated on the test form.  So if the average is used in the calculator, then our car is really doing much better than the 2010 Taurus and Caravan.

Whatever the answers to that, it's very clear that our car does not spew out 16 times as much pollution as newer cars.  So that means there is some very serious misinformation being spread around by government agencies etc. about old cars being "dirty".  And it also means these "cash for clunkers" programs may be based on false information.

I'd readily agree older cars are more likely to pollute more, but probably it would be far more cost effective and environmentally sensible to even subsidize people to get their older cars running in top shape rather than send them to the crusher and build new ones to be sold to people with thousands of dollars in rebates.  Of course, our economic models favor the latter.

It depends on the car..and naturally, the gov't will choose the worst case scenario.  IIRC some early 90s Dodge Dakotas don't have an EGR set-up.  And they won't pass the emissions of a modern car.  They pass their years emissions...but when compared to a new car fail horribly.

But yea..I mostly agree.  It's a cash grab.

[G35X]

19 times more harmful pollutants? That’s possibly comparing 2004 ULEV2 to the pre-1980 level. Your 1990 Dodge Spirit met the 1981 US regulation when new and at that time already it was about 4 times better in the HC emission, more than 4 times better in the CO emission and 3 times better in the NOX emission than pre-1975 cars. And if its cat converter is in good shape, it should pass the BC Air Care easily.

Here is a simple explanation on the automotive emissions:
HC remains in the exhaust when the fuel/air mixture is too rich in the combustion chamber (not enough oxygen to turn all the C in the fuel into CO2). Since engine starts out with rich mixture especially when cold automakers use all kinds of tricks to minimize the duration of the rich period when warming up. Older cars might not be designed with enough consideration in the area such as quick warm-up plumbing and closed-loop exhaust sensor system.

CO2 is the product of burning fuel and its amount is directly proportional to the amount of fuel burnt.  There is no (practical) way to reduce it or convert it into something harmless once it is produced. In other words, CO2 emission is in general proportional to the engine displacement.  Since good fuel mileage is a good selling point (as well as government mandate) automakers are trying to improve it spending a lot of money.  Hybridization, direct-to-cylinder fuel injection, higher compression ratio and idling stop are but a few of the technologies they are using. 

NOX is produced when N2 in the air inhaled into the combustion chamber is exposed to high temperature and O2.  It is turned back into N2 and O2 in the first stage of the 3-way platinum cat converter.  The O2 thus separated is then used to oxidize HC and CO in the exhaust at the second stage turning them into H2O and CO2.

As for BC’s Air Care, yes, it is a cash grab. The amount of harmful emissions reduced by the program is negligible, if any.  CO2, although it may be causing global warming, it is not a harmful element as far as air quality is concerned.

[X-Traction]

Thanks for the explanation, G35X.

The Spirit is in nice shape, straight, no rust, everything works, its 3.0V6 means it has plenty of power but it can also get over 40mpg on the highway.  I've made upgrades such as adding sound insulation.  But when I hear that older cars such as it are really bad polluters, I get thinking it would be socially responsible to replace it.

When I thought about its latest Air Care scores, I wondered if the claims about how dirty older cars are could possibly be accurate.  It turns out that an older car like the Spirit (if in good shape) is only marginally more dirty than a new car.  And we only drive it about 3000km per year.  It pi__es me off that blatant lies are being told to promote these cash for clunkers programs.  This is even worse than the nonsense being spread about wasting electricity.

I emailed Air Care to find out how they arrive at their average scores, but have yet to hear from them.  I can see they have an interest in not revealing such information.

As for a government cash grab, Air Care is operated by a US company, so presumably the profits go south of the border.  Given our government, I wouldn't be surprised if it's even subsidized. 

Luckily our newer vehicle is exempt from Air Care.  I wonder what will happen as most vehicles enter the exempt years.

[rrocket]

Well technically they aren't lying...they're just skewing the results for their favor.

For example, the vehicle that is 16 times dirtier is a V8 pickup truck with no EGR system on it.  And they're comparing it to some 4 cylinder ULEV vehicle.  So it's true that the truck IS dirtier....they're just not being 100% truthful in how they make that claim.

[darrylp]

This is something hard to digest. I mean how can old cars which dates back to 1992 be more cleaner??? If the older cars were less polluting why are the car companies giving importance in inventing more fuel efficient, cost efficient and eco friendly cars?

[rrocket]

This is something hard to digest. I mean how can old cars which dates back to 1992 be more cleaner??? If the older cars were less polluting why are the car companies giving importance in inventing more fuel efficient, cost efficient and eco friendly cars?

No...you misread.  Older cars are 16 times DIRTIER.  Not cleaner. 

[X-Traction]

This is something hard to digest. I mean how can old cars which dates back to 1992 be more cleaner??? If the older cars were less polluting why are the car companies giving importance in inventing more fuel efficient, cost efficient and eco friendly cars?

The emissions testing shows maximum allowable scores, the average scores of cars that passed, and the scores for the car tested.

Not only did our 1990 car pass all tests, but it scored about 1/3 as high as the average passing score.  (As for total carbon emissions, we only drive it about 3000km per year, vastly less than the 16,000km average.)

I'd heard a lot of bs about older cars like this one being 16 or 19 times as polluting as newer cars.  The only way that could be true is if the maximum allowable scores are 16 or 19 times as high for old cars as for newer ones.  I checked and found cars like ours (but not OURS) get scores a little higher than new cars similar to it.  Not 16-19 times as high, but, say, 15% higher. 

This also makes sense in that our car gets mileage very similar to newer cars of similar size and weight.

My peeve is not against the emissions testing itself.  I'm sure it helps keep the worst polluting cars off the roads.  Although it peeves me that I have this annual expense and hassle because some people are too stupid to keep their cars in proper shape.

My peeve is against the costly government programs to get older cars off the road, using the false claim that they pollute 16-19 times as much as newer cars.  If the older cars were evaluated at, say, 20% worse, and based on mileage driven, those programs would be shown to be a huge waste of money.  Better to spend a bit of it to upgrade the power plants in perfectly good older cars.  That would save the embedded energy needed to build new cars and employ a lot of mechanics.  Why should I be able to get $3000 to buy a new car, but not a dime if I spend $1500 for new heads to clean up my car's engine?

Crushing perfectly good old cars makes us poorer.  You don't create wealth by wasting.

The reason why newer cars aren't hugely more efficient is that pushing a certain frontal area through the air at certain speed takes a certain amount of energy.  The internal combustion engine wastes most of its fuel's energy in the form of heat, and nothing much has been done about that for a long time.

It's just hard to improve mileage on a reasonably streamlined 2800lb sedan with fuel injection, lockup 4-spd automatic, intact emissions components such as a good catalytic converter, perfect alignment and properly inflated tires.  Like our Spirit.

Newer technology saved weight in some aspects, but weight was added for crashworthiness, sound insulation, and additional features.  People just bought large suv's (with superfluous 4x4 drivetrains) instead of large sedans.