not sure if anybody has posted gas analyzer readings on this forum yet but i'm from california and somewhat obssessed with emissions. i had extra time today and decided to see how the rx8 does.

one thing i found out about the rx8 is that the dual exhaust is not fully 'functional', (for lack of better terms). i couldn't get a reading when i stuck the analyzer on the driver's side exhaust, which only means that little or no emissions is coming out of it, (i.e. no CO2 reading). the passenger's side tailpipe however, provided accurate readings.

here are the readings: (btw: my rx8 with 18,877 miles is stock with only a revi intake & duct. fuel: 89 octane shell).
measured in PPM.

idle:
HC: 5 CO2: 14.8% CO: .00% O2: .01% NOX: 15


2500 rpm
HC: 4 CO2: 14.9% CO: .00% O2: .00% NOX: 3


just for comparison, a buddy tested a daily commuter corolla with 90,000 miles with new spark plugs and air filter. i know, 2 different cars, but the corolla is supposed to be a low emissions vehicle.

idle:
HC: 90 CO2: 13.8% CO: .50% O2: 1.15% NOX: 80

2500 rpm:
HC: 88 CO2: 14.0% CO: .80 % O2: 1.0% NOX: 45


*'93+ HC should be under 100 ppm, CO should be between .5 - 1.0%, O2 should be .5 -1.0%, CO2 should be 14.7% (full combustion, supposedly), and NOX should be under 100. (CA law))


hopefully this post was found useful by some members. i also did this because i'm planning on getting an exhaust real soon and wanted to compare the before and after.

conclusion, well you guys are smart enough to form your own based on these readings.

 

RX-8s don't have a dual exhaust, just a dual tailpipe

next time block off the side you're not reading from so it all comes out the side you are, assuming you really want accurate readings

 

5 and a 4 on the hydrocarbon analyzer? That is zero for all practical purposes, HC analyzers aren't that accurate.

 

Heh that corolla has seen better days. It ain't burning too well, but with 94k miles I'm not all that surprised. The 8 is lookin pretty good. Can't say I know much about NOx emissions as I was trained with primarily a 4 gas. But I would've thought NOx to be lower at idle, I guess it just goes to show how hot things get in the rotary.

Anyways thanks for posting up. I enjoyed the analysis

 

-yeah, i blocked off the driver's side exhaust while getting the readings.

-i've never seen a car have anything lower than 3 or 4 HC in the dynamometer in our shop. fuel injected cars that go on our analyzer usually average 50 - 85 HC @ 2500 rpms (of course, they're 5 or more years old). regardless, i'll take a 5/4 any day in my 2 1/2 year old 8.

-nox and hc go down as the engine is ran at higher rpms.