04-13-2013, 09:46 AM
|
#1 (permalink)
|
|
Cyborg ECU
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts
|
California emissions and tall transmissions
So, IIRC, the California smog test runs the car at a handful of different speeds measured in mph, not rpm, and tracks emissions. If my car runs at lower RPMs at those speeds due to 20% taller gearing, will it also show lower emissions?
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
|
|
|
|
 Today
|
|
|
|
Other popular topics in this forum...
|
|
|
|
|
04-13-2013, 10:16 AM
|
#2 (permalink)
|
|
Master EcoModder
Join Date: Sep 2009
Posts: 5,927
Thanks: 877
Thanked 2,024 Times in 1,304 Posts
|
Makes sense lower RPM slightly higher load should produce at least lower volume of emissions. Not sure about percentage content which is how the gas hogs get away with their volume.
regards
Mech
|
|
|
|
|
04-15-2013, 10:32 AM
|
#3 (permalink)
|
|
Batman Junior
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,515
Thanks: 4,062
Thanked 6,960 Times in 3,604 Posts
|
My experience: http://ecomodder.com/forum/showthrea...since-126.html
Still well within spec.
The numbers vary so much from year to year, even when no other changes have been made.
Another suggestion: pump up the tires if your test is on a dyno.  |
|
|
|
|
The Following User Says Thank You to MetroMPG For This Useful Post:
|
|
|
04-15-2013, 10:51 AM
|
#4 (permalink)
|
|
Cyborg ECU
Join Date: Mar 2011
Location: Coastal Southern California
Posts: 6,299
Thanks: 2,373
Thanked 2,172 Times in 1,469 Posts
|
Thanks for this, Metro and Old Mech. Looks like the gearing will have little relevance, which is fine. Last time I barely passed on one category (I forget which), but I have replaced the O2 Sensor as the tech recommended (it was original from 1998, I think).
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
|
|
|
|
|
05-09-2013, 07:14 AM
|
#5 (permalink)
|
|
efficiency expert
Join Date: Jun 2008
Location: Northern Utah
Posts: 6
Thanks: 0
Thanked 0 Times in 0 Posts
|
Taller gearing increases the load on the engine, thus emissions tend to suffer. But if you could go 20%, that might be enough to force the transmission into a lower gear, which should help. Besides, 20% less cruise RPM doesn't necessarily mean more MPG anyway. Try it if you wish.
|
|
|
|
|
