Emissions laws...don't seem to make sense

[Straz85]

Maybe someone could make sense of this, because I sure as hell can't. A while back I was at audi.com, and just to see how much my car costs new I built a TT on the website. I put in my zipcode after I chose the TT225 model, and it said something to the effect of "the TT225 is not available in MA, VT, NY, CA and any other states that have adopted CA emissions laws." How is it that a 4 cylinder that gets 30 mpg doesn't meet emissions laws but a Mustang or one of those new Chrysler "muscle cars" that gets like 15-20 mpg does?

[vw.audi-tech]

Emissions Laws are not about how many MPG the engine uses , but specifically how much comes out the tailpipe. When a Manufacturer produces a vehicle they wish to release to the public they have to undergo Federal Test Procedure (FTP), which is federally governed. If States decide to up the emissions laws in that paticular state above the federal level, Manufacturers have to prove that they can also meet those standards to be sold in that state. California Emmisions is the stricktest in the US and if a vehicle meets California Air Resources Board (CARB) guidelines it will have no problem anywhere else in the US. I am sure that it will be done at some point, Manufacturers dont want thier cars excluded from sale in any state.

Kevin

[Straz85]

Originally Posted by vw.audi-tech

Emissions Laws are not about how many MPG the engine uses , but specifically how much comes out the tailpipe. When a Manufacturer produces a vehicle they wish to release to the public they have to undergo Federal Test Procedure (FTP), which is federally governed. If States decide to up the emissions laws in that paticular state above the federal level, Manufacturers have to prove that they can also meet those standards to be sold in that state. California Emmisions is the stricktest in the US and if a vehicle meets California Air Resources Board (CARB) guidelines it will have no problem anywhere else in the US. I am sure that it will be done at some point, Manufacturers dont want thier cars excluded from sale in any state.

Kevin

So what is it about cars that can change the emissions. In theory (in my head at least) it should be directly proportional to the gas milaege. All cars are burning the same gas, so the byproducts should be the same. If a car gets 15 MPG it's burning twice the amount of fuel as a car getting 30 MPG, and since the fuel is the same, and since the reaction is the same, the exhaust gases should be ther same formula, just twice the amount frm the 15 MPG car. The only thing I can think of that would change that on a car is the catylitic converter.

What I was thinking is maybe they say "okay, if the car is a 4 cylinder this is how much emissions it can put out, if it's a 6 cylinder...and so on.

[Handeye]

Here in TN, we have emmissions testing in Davidson (Nashville) and all the surrounding counties. The only reason we have them is so that the state of TN can get extra federal funds to expand the road system.

The testing consists of a visual inspection of the exhaust to ensure that there is a cat in place. The gas cap is pressure tested, and an exhaust sniffer test. If your car has OBDII it is only hooked up to their computer and monitors the O2 sensors.

If you get the sniff test, it is mostly looking for hydrocarbons. These are only expressed in parts per million, so an amount based on MPG is not taken into concideration.

[Straz85]

Originally Posted by Handeye

Here in TN, we have emmissions testing in Davidson (Nashville) and all the surrounding counties. The only reason we have them is so that the state of TN can get extra federal funds to expand the road system.

The testing consists of a visual inspection of the exhaust to ensure that there is a cat in place. The gas cap is pressure tested, and an exhaust sniffer test. If your car has OBDII it is only hooked up to their computer and monitors the O2 sensors.

If you get the sniff test, it is mostly looking for hydrocarbons. These are only expressed in parts per million, so an amount based on MPG is not taken into concideration.

But passing emissions and whether or not it can be sold in a state because of emissions are not necessarily the same thing. You can buy a used TT in MA and it will pass just find, but they won't sell new ones.