Archives

I'm puzzled about something : Which of these two cars would be cleaner ...a new car that is rated as an ULEV and gets 30 miles per gallon, or an older model car that gets 60 miles per gallon, but is rated at the older emissions standard ?

Since the newer car burns twice as much gasoline, I would think it would pollute twice as much . ( Although I know this not to be true. )
Still though, the 'cleaner' car is burning twice as much gasoline ... at what point would the two be equal ?

( And can the newer emissions devices really make up for that much pollution ?? )

Thanks !

Hi Wannabeclean:

___Unfortunately, that is not how it works with SMOG based emissions but is exactly how it works with CO2 (the GHG emission).

___SMOG based emissions are collected from a vehicle as it is performing the EPA FE test in a bag and the contents are analyzed. It doesn’t matter if it received 24 mpg (Accord) or 60 mpg (Prius II) in the test, the analysis of the bag is what determines its Federal and CARB emissions ratings. The Accord PZEV received just 24 mpg on the FTP75 and its emissions were analyzed to Tier II/Bin2 (FED std.) and SULEV-2 per the CARB ones. The Prius II received 60 on the same test cycle and its emissions were collected and measured with the resultant Tier II/Bin3 rating per the FED and SULEV-2 per CARB. In terms of SMOG forming emissions, the PZEV based Accord is actually cleaner then the Prius II. As it the HCH-I, HCH-II, and 2007 Accord Hybrid then any other automobile other then the NG based Honda Civic.

___PZEV is an SULEV-2 (smog forming emissions rating) with almost zero evaporative emissions and that is measured w/ warm and cold block temps over as much as a 24 hour period. We will leave that one out of the discussion for now.

___In terms of GHG’s however, a gallon of gasoline consumed released ~ 19.6 #’s of CO2 once consumed. The Prius at 60 mpg over a 60 mile distance (if it receives 60 mpg over that distance) releases 19.6 #’s. The Accord would release 49#’s. This does not include pumping, refining and transport which adds another almost 9#’s of CO2 per gallon consumed. The Prius is by far the lowest CO2 producer of all cars available in the US today since the Insight has been put out to pasture.

___Good Luck

___Wayne

Thanks for that information !
What can I do to an older car such as a 1993 Honda Civic to reduce its emissions ?
I have bought a Bosch oxygen sensor, and have done the usual tune up ( oil, plugs , filter,fuel filter,wires, and a bottle of injector cleaner in the gas tank ), but what else can I do ?
I notice the car has a charcoal canister. Should it be replaced ?
Isn't there any parts I can add to the car to reduce the emissions ?

Hi Wannabeclean:

___I should have been more specific about emissions ratings and real world emissions. Your 93 Civic was probably rated as a TLEV and driving for maximum FE will help reduce both the SMOG and GHG based emissions depending on the NOx spikes during re-ignitions. It is just that there is only so far you can go with this :( Keep your tires inflated, a HQ synthetic, install a new air filter and a semi-annual tune up is about all you can do. There may be more efficient after market CAT’s but one more then likely change the back pressure which can lead to all kinds of unfortunate problems :( The OEM CAT that is currently installed has probably seen better days as most are designed to meet a given spec over a given distance and a 93 is more then likely surpassed the 80K miles the EPA used to demand. Simply try and maximize your FE and/or minimize your driving the best you know how and leave the real SMOG based emissions reduction to your next automobile.

___Good Luck

___Wayne

I read the above but still need a bit of clarification please:

Do the ULEV and SULEV ratings measure the MASS of pollutants emitted or simply their CONCENTRATION? I know the CO2 ratings do measure mass, but this question concerns smog pollutants only.

My impression is that they are simply concentration ratings. If this is true, is there a volume measurement that one could use to determine say grams/mile of nitrous oxides, etc to compare various vehicles?

I'm thinking that, say, a Chevy Trailblazer and my MT Insight could both be ULEV, but I would think that the Trailblazer would belch forth a larger AMOUNT of smog-producing pollutants per mile given its greater fuel consumption. But maybe this is not so?

If mass of pollutants is strongly mileage related, how about creating a cleanmpg ranking chart for pollutants/mile (by type) for various vehicles?

___In terms of GHG’s however, a gallon of gasoline consumed released ~ 19.6 #’s of CO2 once consumed. The Prius at 60 mpg over a 60 mile distance (if it receives 60 mpg over that distance) releases 19.6 #’s. The Accord would release 49#’s. This does not include pumping, refining and transport which adds another almost 9#’s of CO2 per gallon consumed. The Prius is by far the lowest CO2 producer of all cars available in the US today since the Insight has been put out to pasture.

___Good Luck

___Wayne

This is probably going to be a dumb question: How can 19.6#'s or 49#'s of CO2 be released from a gallon of gas that only weighs 6-8 pounds?

Hi Lightfoot:

___It is concentration other then CO2 as a %. The FED and CARB limits are listed as a g/mile if that helps?
The concentrations for HC, NOx , HCO, LCO, and CH4 are in parts per million (ppm), and the concentrations for CO2 are in percent (%).

___Larry, this should help: How can 6 pounds of gasoline produce 20 pounds of CO2? (http://www.fueleconomy.gov/feg/co2.shtml)

___Its the 14.7:1 fuel air ratio that brings the 6 #’s of gasoline up to 19.6 #’s of CO2 output since you burn a lot more gallons of air with a gallon of gasoline then the gasoline itself.

___Good Luck

___Wayne

Thanks!

Did a bit of digging on my own and found this which IS in grams of pollutant/mile:
http://www.epa.gov/autoemissions/detailedchart.pdf

So it appears that the EPA comparative rankings ARE based on amount (mass) of pollutant, not concentration (albeit trusting the mfr's test data to be accurate!). This should zero out differences in gas consumption, as well as differences which may result from air pumps adding fresh air into the exhaust to complete combustion and perhaps dilute the exhaust gases a bit.

www.fueleconomy.gov will show you fuel consumption versus emissions output (in tons,) You can configure the fields to your annual miles and percent of in town/out of town driving.

This is way over my current level of education in emissions, but really interesting. I noticed that many people driving the same model car, listed something different in their profiles, and many just selected "unknown." I contacted my vehicle's manufacturer a couple of times, and they finally understood what I was asking. They said my 2005 Aveo is LEV-2 (low emmisions vehicle- but I don't know what the 2 means). ULEV = ultra low, SULEV = super low. How can people find this out for their vehicles, in order to update or correct their profiles?

Thanks for that information !
What can I do to an older car such as a 1993 Honda Civic to reduce its emissions ?
I have bought a Bosch oxygen sensor, and have done the usual tune up ( oil, plugs , filter,fuel filter,wires, and a bottle of injector cleaner in the gas tank ), but what else can I do ?
I notice the car has a charcoal canister. Should it be replaced ?
Isn't there any parts I can add to the car to reduce the emissions ?

Typical tune up is the ticket for increasing efficiency and decreasing emissions. You will want to make sure all of your evaporative emissions hardware is functioning properly, as problems with these things typically don't set Check Engine lights on the older cars. Make sure the PCV valve is clean and working properly also. Check all vacuum lines for leaks, cracks etc.

The D15 engine is pretty phenomenal considering it is 20+ years old now and still can get the FE of some newer stuff!

Go to www.fueleconomy.gov

Find your car.

Go to Air Pollution Score. Click on "Show Detailed Air Pollution Information"

Click on "How to Identify a Clean Car"

There's a serial number on various parts under the hood. Match it with the aforementioned information.

For me, I found "7TYXV02.4HXA" so I've got a SULEV-II.

Any EV that uses solar panels to recharge the batteries. A vehicle doesn't get any cleaner than that. :)

Alphabetbackwards, that is a nifty tip. Unfortunately, for my model year, there is no data on this. There is on the 2006, the 2007, and the 2008, but not on the 2005. Still, that is a nifty way to find out what your car engine was designed to. I hope others can make use of it, to clear up all those "unknowns"

A 1993 model isn't going to be competitive with newer cars as far as emissions go. Several reasons: 1) Better sensors, faster computers, better engine design lets new cars run cleaner by design, 2) Parts age, especially things like oxygen sensors and catalytic converters. Buildup inside the engine contributes to higher emissions, 3) Regulations have gotten much more strict.

Obviously a car owner can't redesign their engine or force the manufacturer to make a car way cleaner than the law requires or recognizes, but for older cars, besides the typical tuneup one can replace the oxygen sensors and catalyst (somewhat expensive, only do it if you know from a smog test that yours are compromised), and keep the engine clean. Uneven buildup on the injectors can cause problems, as can cylinder deposits. Use gas with more detergents, and/or fuel additives.

This is probably going to be a dumb question: How can 19.6#'s or 49#'s of CO2 be released from a gallon of gas that only weighs 6-8 pounds?

The Carbon C comes from the Gasoline... the Oxygen O2 comes from the air... so burning Gasoline has the mass of the Carbon from the gasoline + the mass of the Oxygen from the Air... and then the Hydrogen from the fuel combines with Oxygen from the Air to form water.

14.7: 1 stoichiometric afr. So theoretically for every 1 unit of mass of gasoline you will get 15.7 mass units of product.

Any EV that uses solar panels to recharge the batteries. A vehicle doesn't get any cleaner than that. :)

Except maybe a fuel cell vehicle, but of course none of those are yet in production. Has anyone calculated the environmental cost of battery disposal?

Hi 93Hatch:

___Toyota has and does so not just on a hybrids battery but everything including the large P/U’s and SUV’s they make from dust to dust.

___Good Luck

___Wayne

Except maybe a fuel cell vehicle, but of course none of those are yet in production. Has anyone calculated the environmental cost of battery disposal?

Lead-acid and Ni-MH (hybrid batteries) are almost 100% recycled.

Cars are very, very heavily recycled in the US right now.

Metal prices are up. :D

Lead-acid and Ni-MH (hybrid batteries) are almost 100% recycled.

Cars are very, very heavily recycled in the US right now.

Metal prices are up. :D

I suspected that, but wasn't sure.