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I need some hard numbers for what all the standards mean. I can look up my car's output but it was before these standards and I'd like to compare at least.

For example, my car will be putting out 3.7 tons/year according to the EPA, which is the same as the 06 HCH, but I dunno if that just means it'd be qualified the same as the HCH or do drivetrain issues come into play?

Thanks!

Hi SVOboy:

___Go over to EPA.gov and use the search text box. You can bury yourself for weeks inside there and when you are done, you will have a handle on emission far greater then you may have wanted.

___Your 91 CRX w/ an Auto (29/34) appears to emit 5.9 tons of CO2 if you were to receive the ~ EPA combined based off of 45% highway and 55% city over 15,000 miles. Because of its age, it was not subject to the TLEV or better emissions specs of the time. TLEV + specs were initiated in 92 moving forward.
The older cars are pretty much spewing the worst of everything on the road in terms of SMOG related emissions unfortunately :( Some do absolutely stunning in terms of GHG’s however!

___Good Luck

___Wayne

Ah, smog, I'll have to learn about that. I'm using the 3.7 based on the engine/transmission combo (as well as emissions equipment) that will be running in the car.

I wonder what can be done to improve it.

Hi SVOBoy:

___With every additional piece of Emissions HW, there is usually a hit in FE unfortunately for us all. About the only thing you can really do is to try and receive the best FE you can to reduce whatever emissions are being output. I have not heard of anyone adding a more robust CAT and setting up pre and post CAT O2 sensors along with coordinating that with the AIT, ECT, advance, Closed and open loop ops, and the MAP via the ECU and I wouldn’t want anyone to try as it sounds like an engineering nightmare!

___Where does the 3.7 you are posting come from? Ton’s of CO2 would be much higher for a 40 mpg automobile unless you were traveling far less then 15K miles per year which is the best solution of all by far!

___I like Dan’s Del Sol emissions ratings best. Emissions: Yes and/or sometimes ;)

___Good Luck

___Wayne

3.7 comes from the CRX HF that's rated for 51/56, I believe. I might've picked the wrong one but that's the hardware I'll be using.

Engine off coasting I think will be good for emissions.

Also, I'm going to be swapping my stock exhaust with the cat at the end of the downpipe for one with the cat at the end of a very short intake manifold, which makes the cat heat up really quickly, helping warmup emissions seriously, which I like.

*shrug* I dunno.

Hi SVOBoy:

___A CAT closer to the exhaust manifold does indeed help with faster light off. Most automobiles today in fact have that CAT just down stream for that very reason. Whether this is a good mod or not, I have no idea. Back pressure at or near the manifold may be a bit high with the CAT that close and if it was not designed to be there … I just don’t know. Be careful with this.

___You own a 91 CRX DX w/ Auto - EPA rated at 29/34, correct? I cannot be sure but I doubt there is just a tranny swap difference between the CRX and the non-California based CRX HF from 91 w/ the EPA rating of 49/52? With a few google searches, you may be able to find out if it is the exact motor or if the HF is a lean-burn capable ICE. If the HF is a lean-burn capable ICE, then you have a lot more to do to make your DX into an HF unfortunately …

___Right on about ICE-Off! A small issue in regards to ICE-Off to ICE-On however. There is usually a NOx spike and I have to imagine the spike back in the pre TLEV regs days would have been a monster to control. Nothing you can probably do about it with the analyzers, tools, and HW available to you but it is something to consider.

___Good Luck

___Wayne

I was wondering about the NOx spike... does this still happen if I'm coasting and use compression (i.e. drop the clutch) to start it up? It seems like starting it with the starter and key might do this because more fuel might be injected than is needed (just to make sure it starts), while dropping it into fifth at 55mph almost seems like something that'll result in the normal injector firing pressure because there's already enough force from the transmission to get the engine going.

Good question. Seems like your logic is sound. The engine is picking up where it left off, so to speak- the normal start logics are not used. I'd love to see some dyno and tailpipe results on an experiment like that!

SVO- Xcel is soo right about EPA.gov. He steered me in there a year ago and I still haven't digested it all! Its a veritable forest of information in there- a little tricky to navigate, so take notes on what you read in case you can't find it quickly again!