Matt D.
12-16-2004, 11:05 AM
I took this from my friend on MNSC. Give him (Joel, aka Zola (http://www.mnsportcompacts.net/forum/member.php?u=208)) credit for the work he did to create this. Original thread HERE (http://www.mnsportcompacts.net/forum/showthread.php?t=11422).
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For those of you unfamiliar with the topic, Minnesota has some of the worst quality gas in the nation (in performance terms). Throughout the 1990s, the EPA put dozens of metropolitan areas throughout the country into a scheme requiring them to put additives in gasoline to reduce cold weather emissions. Not surprisingly, those additives hinder performance, more specifically making the gasoline burn much faster, which in turn will cause learning ECUs to noticeably scale back the amount of ignition advance they run.
In the past few years most metro areas nationwide have reached the air quality targets set by the EPA and have thus come off the Winter Oxygenate program. As you can tell from this document (http://www.epa.gov/otaq/regs/fuels/oxy-area.pdf) however...Minnesota has implemented its own statewide, year-round program for adding oxygenation to our fuels.
This has really been an issue for heavily modded Subaru owners in the Midwest (most of us using the TurboXS UTEC engine management), as people are noticing unchanged tunes running half an air-fuel point leaner due to winter gas. So in order to avoid issues, many people have had to do some combination of turning down boost, richening up their fuel maps, or retarding timing. Or find a steady supply of race gas.
Anyway, my car prefers non-oxygenated gas, as evidenced by piles of datalogs. So I've taken the Twin Cities stations from these two lists:
* http://www.mnssa.com/Non.html
* http://www.msra.com/NonOxygenatedFuel/NonOxyList08.16.04.pdf
...and geocoded the addresses and plopped them onto a map. Hopefully this will prove useful for some people besides me.
Map (3.2MB PDF):
http://www.socsci.umn.edu/~jkoepp/mnsc/NonOxygenated.pdf
Key (showing names and addresses of the stations):
http://www.socsci.umn.edu/~jkoepp/mnsc/key.txt
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For those of you unfamiliar with the topic, Minnesota has some of the worst quality gas in the nation (in performance terms). Throughout the 1990s, the EPA put dozens of metropolitan areas throughout the country into a scheme requiring them to put additives in gasoline to reduce cold weather emissions. Not surprisingly, those additives hinder performance, more specifically making the gasoline burn much faster, which in turn will cause learning ECUs to noticeably scale back the amount of ignition advance they run.
In the past few years most metro areas nationwide have reached the air quality targets set by the EPA and have thus come off the Winter Oxygenate program. As you can tell from this document (http://www.epa.gov/otaq/regs/fuels/oxy-area.pdf) however...Minnesota has implemented its own statewide, year-round program for adding oxygenation to our fuels.
This has really been an issue for heavily modded Subaru owners in the Midwest (most of us using the TurboXS UTEC engine management), as people are noticing unchanged tunes running half an air-fuel point leaner due to winter gas. So in order to avoid issues, many people have had to do some combination of turning down boost, richening up their fuel maps, or retarding timing. Or find a steady supply of race gas.
Anyway, my car prefers non-oxygenated gas, as evidenced by piles of datalogs. So I've taken the Twin Cities stations from these two lists:
* http://www.mnssa.com/Non.html
* http://www.msra.com/NonOxygenatedFuel/NonOxyList08.16.04.pdf
...and geocoded the addresses and plopped them onto a map. Hopefully this will prove useful for some people besides me.
Map (3.2MB PDF):
http://www.socsci.umn.edu/~jkoepp/mnsc/NonOxygenated.pdf
Key (showing names and addresses of the stations):
http://www.socsci.umn.edu/~jkoepp/mnsc/key.txt