dasams

This is correct. CA, and especially LA and the Central Valley, are ozone non-attainment areas meaning that the air quality does not meet EPA standards. CO and NOx are ozone precursors and CARB regulated gasoline composition to reduce their presence in tailpipe emissions.

One of the requirements is reduced gasoline sulfur which is achieved through deeper hydrodesulfurization which, unfortunately, also reduces octane. Back in the 90's, this led to a situation where the CA gasoline pool became octane constrained. The solution was to reduce premium octane to 92. This didn't last long as the situation deteriorated and the octane was reduced again to 91. So no conspiracy, just a fact of life of gasoline refining.

BTW, gasoline sulfur content will continue to drop and other parts of the country will also become octane constrained. Hence, do not expect 93 gasoline to always be available. dave

SAN997

I think the reason California gas was one of the first to go to 91 octane and stay there was the state ban on MTBE around 2002-2003:
http://www.icis.com/resources/news/2...tbe-in-the-us/

MTBE has an octane rating of about 112 (R+M)/2. So they would blend this with fuel in California up until end of 2002. I left the state in 2002, incidentally, and remember 93 octane. After I returned recently, I noticed it is gone everywhere.

You can read more about MTBE here:
http://www.acfa.org.sg/pdf/MTBE%20&%...erformance.pdf

Now the question becomes, can you still buy industrial MTBE and blend it yourself??

voiceprint1

91 and lower grades do make a difference in air quality in LA, the smog used to be much, much worse, it still ranks among the worst in the world though.

PCA1983

Cylinder knock sensors detect predetonation and dial back on ignition mapping to prevent knock. Power drop with 91 octane would probably not be noticeable on cool days. On a hot day u could expect more power loss, especially if a turbo.
No reason not to use 93 octane here in FL tho, with it priced at only $2.33/gal

Tsilnner

This has been addressed in other threads, but the 10% alcohol added by law in CA bothers me more than the 91 Octane limit. Now there is a push to increase it to 15%, and several members, much more knowledgeable in the area than me, have indicated this might harm our high compression engines.

You can buy nigher octane gas in CA- if you live here do a search for the locations on line. However, I was told, perhaps someone here knows, that that gas has over 10% alcohol. I once filled up my E39 M5 with 100% of the high octane gas at a Union 76 station and my catalytic converters burned out a few weeks later. Coincidence? Perhaps, but I was still on warranty and did not bother to mention that fill-up to the dealer...

I know that there are emission arguments for the use of alcohol, but I would agree with the other posts in this this thread that the use of alcohol is pure politics. Iowa corn, grown by big ag, is in concert with big sugar in FL to push their product on the driving public.

Last, one of the arguments for alcohol in gasoline is that it helped make the US energy independent, but now, with oil from shale and fracking, alcohol is no longer needed as we are, with natural gas, an energy exporter.

jhbrennan

Goof luck convincing the farmers and the corn lobby that ethanol isn't needed to be blended with gasoline.

DC911S

Corn lobby in Red States need federal welfare too, even if they complain when others get it too. Same for sugar lobby.

dbv1

It's not hard to tell the difference between 94 and 91 on track but at one point I ran 100 and it made no difference compared to 94. Anybody else notice the same or did I get stiffed?

<fire suit on>

Higher octane fuel reduces pollution, not the other way around:

http://news.mit.edu/2014/premium-gas...uel-money-1028

But it seems that high octane cuts into refiner's profits so you guys only get 91:

http://www.superstreetonline.com/fea...-technobabble/

Ethanol isn't very good for engines:

http://www.fuel-testers.com/ethanol_...ms_damage.html

Ethanol isn't all that great for the environment either (think deforestation etc for corn fields):

http://occupytheory.org/advantages-a...es-of-ethanol/

<fire suit off>

PCA1983

Many people and politicians dont want to hear it, but burning one of the world's most valuable food crops in our cars has the worldwide effect of starving many millions of people in the third world.
The USA now has a reservoir (among others) with recently proven reserves of 3 Trillion bbl of recoverable oil. More proven reserves than all of OPEC combined. More than Saudi Arabia had a century ago before any of their oil wealth was ever tapped. That is a lot of untapped wealth even at $50/bbl.
Plus electric cars and small automated driving appliances that take people to work in congested commutes, and out in the evening on pub crawls, will soon be commonplace.
A guess is that some things will soon change... uhmm, maybe change is already happening and set to explode. There could be a lot of prosperity ahead.
Then we can have any fuel we want for our sunny day blasts in our Porsches!

jsalah

I'd like to comment on a few things in this thread, but as they deal with politics and I try very hard to stay FAR away from politics in the bizarre RL world, I won't...

I will, however, say THIS is brilliant. Very well put. One day I may have to quote you in my signature like I see others do around here...

Tj40

Sounds like the old one = 'Horsepower sells cars but Torque wins races'

dasams

Every morning, the birds chirp and shortly thereafter the sun rises. Did the birds cause the sun to rise?

It's true that MTBE is a great octane enhancer and its ban created an octane shortfall. But the more important fact is that modern engines produce very clean emissions so long as the catalysts employed are not poisoned. So clean gasoline is a must. And the cleaner the gasoline, the lower the octane, all else being equal. Ethanol, also a great octane enhancer, to the rescue. But even at a 10% blend rate, it cannot bring the pool back to 93 due to the low octane of the underlying base fuel.

911searcher

Maybe ethanol looks "less sensible" with topsoil seemingly "running out".

https://www.scientificamerican.com/a...ion-continues/

DC911S

Fond days of the dustbowls.....due to over farming and trying to make crops grow on prairie land, that was not really make for crops like corn and other things. Its as dumb as over grazing cattle on federal high desert mountains ranges and prairie too, for not much money.