Emissions Standards - "Good For Fuel Efficiency," Consumption Data Says

[trebuchet03]

This is probably going to rub people the wrong way.... I've listened to plenty of people claim that emissions standards are choking fuel efficiency... But not once did anyone bring any data to the table....

First, a time line (cite: http://www.epa.gov/reg5oair/mobile/history.htm)

1970-1975: The First Standards

* In 1970, Congress passes the Clean Air Act, which called for the first tailpipe emissions standards. The pollutants controlled are carbon monoxide (CO), volatile organic compounds (VOC), and nitrogen oxides (NOx). The new standards go into effect in 1975 with a NOx standard for cars and light-duty trucks of 3.1 grams per mile (gpm).

1977-1988: Tightening Standards for the First Time

* In 1977, Congress amends the Clean Air Act and tightens emission standards again in two steps. First, between 1977 and 1979, the NOx standard becomes 2.0 gpm for cars. Then in 1981, the NOx standard for cars is reduced to 1.0 gpm. Effective in 1979, pursuant to the Clean Air Act requirements, EPA tightens standards for light-duty trucks to 2.3 gpm. Effective in 1988, EPA then sets the first tailpipe standards for heavier trucks at 1.7 gpm and revises the standard for lighter trucks to 1.2 gpm.

1990-1994: Tier One

* In 1990, Congress again amends the Clean Air Act, further tightening emission standards. The NOx standard is set at 0.6 gpm for cars, effective in 1994. The new standard -- called "Tier One"-- is a 40% reduction from the 1981 standard. For trucks, the new standard ranges from 0.6 to 1.53 gpm, depending on the weight of the vehicle.The Clean Air Act Amendments of 1990 also require EPA to assess the air-quality need, cost effectiveness, and feasibility of tighter emission standards for the 2004 model year and beyond.

1998: Voluntary Agreement For Cleaner Cars

* In 1998, the Clinton Administration, with the auto industry and the Northeast states, strike an innovative, voluntary agreement to put cleaner cars on the road before they could be mandated under the Clean Air Act. The new cars are called National Low Emission Vehicles (NLEV). The first NLEV cars under the agreement reach consumers in New England in 1999 and the rest of the country in 2001. NLEV cars operate with a NOx standard of 0.3 gpm, a 50% reduction from Tier One standards. The NLEV agreement also calls for a 0.5 gpm NOx standard for lighter trucks only, a 17% reduction from Tier One requirements for these vehicles.In 1998, as required by the Clean Air Act Amendments of 1990, EPA issues the Tier Two Report to Congress. The report contains strong evidence of the need, cost-effectiveness and feasibility for tighter tailpipe emission standards in the future beginning in 2004. Three main factors support EPA's decision: 1) currently vehicles make up 30 percent of smog-forming emissions nationally, and because the number of miles driven is increasing (up 127% since 1970) they will continue to be a significant contributor to pollution; 2) larger vehicles, like SUVs that currently do not meet the same standards as cars, pollute 3-5 times as much and make up almost 50 percent of the vehicles sold today; 3) the technology to meet tighter standards is available and cost-effective.In 1998, EPA also determines that sulfur reductions in gasoline are needed to enable the full performance of low emission-control devices.

1999: Tier Two

* In 1999, EPA proposes Tier Two tailpipe emissions standards beginning in 2004 -- the first time both cars and light-duty trucks are subject to the same national pollution control system. The new standard is 0.07 gpm for nitrogen oxides, a 77 to 86% reduction for cars and a 92 to 95% reduction for trucks beyond the NLEV agreement. EPA also proposes a reduction in average sulfur levels to 30 ppm (maximum of 80 PPM) to achieve the full performance of vehicle emission control technologies.As part of these new standards, EPA has included several measures to ensure maximum flexibility and cost-effectiveness. These flexibilities include: 1) allowing averaging to meet both the car emission and gasoline sulfur standards; 2) allowing extra time for larger vehicles between 6000 and 8500 pounds and smaller refiners to meet their respective standards; and 3) allowing for a market-based credit trading-and-banking system for both industries to reward those who lead the way in reducing pollution.

If that was too long...

1970-1975 - first emissions standards
1977-1988 - tightened emissions standards
1990-1994 - tier I emissions standards
1999 - tier II emissions standards

Now, fuel consumption over time.


Notice the huge drops in consumption beginning with the first fuel emissions standard. In 1999, the slight upward trend was reversed - I'm not so sure I'd call that significant, but the change in emissions went from .6gpm NOx to .3 gpm NOx (compared the difference to the 1975-1981 -- 3.1gpm to 1.0). There's not enough data to say what the trend is after 2004....

But what about fuel efficiency - the mpg numbers you ask?
Unfortunately, the BTS only has new car mpg data starting in 1980... But, for all cars on the road, data goes back to 1960 (which just means effects lag behind in year)...

So, for all cars on the road

Again, mpg numbers go up immediatly following the emissions standard being put into place... But, after 1990 (tier I) - things stay flat.



Feel free to poke holes - but, if you're going to do so... you sure as hell better back it up with reliable data. My data is coming from the BTS http://www.bts.gov/publications/nati...on_statistics/ - so I'm expecting source quality to at least match that I put the effort in, I'm expecting you to do the same

And one more thing... I couldn't care less about your anecdotal evidence Bring data^

[Lazarus]

Are emissions and CAFE the same thing? There were several changes during those time frame.

Also how do we know that without emissions that the MPG would not also increase. We have no data because the it's illegal to do so but there have been folks that pull emission stuff to get better mileage or run leaner getting higher NOX levels that would not meet the EPA standards but get better FE.

[trebuchet03]

Originally Posted by Lazarus

Are emissions and CAFE the same thing? There were several changes during those time frame.

Also how do we know that without emissions that the MPG would not also increase. We have no data because the it's illegal to do so but there have been folks that pull emission stuff to get better mileage or run leaner getting higher NOX levels that would not meet the EPA standards but get better FE.

I'm sure there's data out there Illegal drugs are... well illegal - but we somehow know about how many people are on them... (But that said, there's plenty of places to poke holes )



One of the things I wanted to bring to the table is that emissions standards doesn't automatically mean lower fuel economy. That is, fuel economy and emissions can coexist. For example, Tier II emissions went into place - and we didn't see any significant change in FE or total consumption.

Additionally, if we think of emissions equipment as a hindrance... Every car has the same requirement to meet - but there's still an increase in the mpg numbers and a decrease in consumption (the mfr's were still able to decrease consumption with the standards in place). What I'd like to know, if I had a time machine, if these standards weren't put in place - would we see the same upwards trends in fuel efficiency?


EDIT: To answer your question... No emissions and CAFE are independent. I've got the data for mpg versus CAFE standards somewhere, I'll look for it.

[Lazarus]

Originally Posted by trebuchet03

I'm sure there's data out there Illegal drugs are... well illegal - but we somehow know about how many people are on them... (But that said, there's plenty of places to poke holes )



One of the things I wanted to bring to the table is that emissions standards doesn't automatically mean lower fuel economy. That is, fuel economy and emissions can coexist. For example, Tier II emissions went into place - and we didn't see any significant change in FE or total consumption.

Additionally, if we think of emissions equipment as a hindrance... Every car has the same requirement to meet - but there's still an increase in the mpg numbers and a decrease in consumption (the mfr's were still able to decrease consumption with the standards in place). What I'd like to know, if I had a time machine, if these standards weren't put in place - would we see the same upwards trends in fuel efficiency?

I don't know just seem like there is a big piece missing. I think the way to tell about the efficiency would be that the FE has continued to climb even though the empty weight of the cars has sky rocketed. I'll leave this discussion for those smarter then I. I look forward to the responses.

[trebuchet03]

Originally Posted by Lazarus

I don't know just seem like there is a big piece missing. I think the way to tell about the efficiency would be that the FE has continued to climb even though the empty weight of the cars has sky rocketed. I'll leave this discussion for those smarter then I. I look forward to the responses.

That's another thing I've been looking for.... vehicle weight over time....

For the Impala... someone posted in another thread...

Year = pounds
1958 = 3,458-3,523
1959 = 3,570-3,665
1960 = 3,575-3,635
1961 = 3,445-3,600
1962 = 3,450-3,920
1963 = 3,265-3,870
1964 = 3,325-3,895
1965 = 3,385-4,005
1966 = 3,430-4,005
1967 = 3,455-3,990
1968 = 3,250-3,940
1969 = 3,640-4,285
1970 = 3,641-3,871
1971 = 3,391-4,021
1972 = 3,720-4,150 -- "In '72, Impala all-time sales topped the 10 million mark, extending its lead as the best-selling full-size car in automotive history"
1973 = 4,087-4,162
1974 = 4,167-4,256
1975 = 4,190-4,959
1976 = 4,175-4,972
1977 = 3,533-4,072 -- "curb weight was cut by more than 700 pounds"

the more current weights are
94-96: 4221lb
00-05: 3465lb

So the weight in 1958 is almost the same as 2005.... This could be isolated, but it strikes my interest strings


But ya, there's a lot missing (I totally agree)... I've got some other points, but If I post it all - I'm worried no one will say anything at all (I'm looking for different perspectives).

Impala info
http://www.goissca.org/imp_hist.htm

[Duffman]

Fuel efficiency should should follow CO & HC reductions. NOx is the one that is fought at the expense of efficiency.

[trebuchet03]

Originally Posted by Duffman

Fuel efficiency should should follow CO & HC reductions. NOx is the one that is fought at the expense of efficiency.

Yes - that's what I've been hearing for so long.... Lower NOx - lower FE.... Except, NOx standards were tightened - and fuel efficiency went up. This suggests R&D went into engine design to overcome the challenge.

What you said is true - for a case by case comparison... But step back and look from the designer perspective (the person being told to make it more fuel efficient AND put out less NOx), not the end user.

[Duffman]

Its taking a narrow view of the situation assuming all your FE gains are due to more efficient combustion. The aerodynamic improvements are absolutely huge. Everything has an OD tranny now. Tires and oil are leaps and bounds ahead. The catalytic converter has to be one of the best devices ever invented. Advances in manufacturing methods and materials deserve great credit, they had the potential to design great cars in the past but couldn’t mass produce them cheap.

To get some perspective though, a 55 chevy could get 25 mpg and its every bit the car as todays midsizes when comparing room and cargo capacity.

[trebuchet03]

Originally Posted by Duffman

Its taking a narrow view of the situation assuming all your FE gains are due to more efficient combustion. The aerodynamic improvements are absolutely huge. Everything has an OD tranny now. Tires and oil are leaps and bounds ahead. The catalytic converter has to be one of the best devices ever invented. Advances in manufacturing methods and materials deserve great credit, they had the potential to design great cars in the past but couldn’t mass produce them cheap.

I never assumed it was all due to combustion (well, maybe implicitly - but by accident ).... What you've posted is exactly my point - the auto mfr's were given standards to meet - and met them while still increasing fuel efficiency (note: I didn't say thermal efficiency). I personally find it interesting that the rate of advancement changed at the same time emissions standards came into play.

It's almost foolish to say emissions standards are causing fuel efficiency to go down - when, in reality, fuel efficiency has gone up or (at least) remained flat.

[Duffman]

Well it is both true and false.

Diesel particulate filters require fuel to function so all diesels this year burn more fuel than last year to be cleaner. Fighting NOx is costing us MPG as well. But you are right that we are getting cleaner every year and FE is holding for the most part. Like I said earlier though, most of the basic tech and theory was available a long time ago, its largely more implemented now though because we have better manufacturing tools to implement it.

edit: I forgot to add as well, changes in fuel formulation have also had a big effect on the cleanliness of cars, and that’s really an external to the idea you are putting forward.