93 octane in Denver? Options

[35th_Anniversary...]

Correct, but if the knock sensors are causing your timing to be retarded, you're loosing power.  You would need a scan tool to know if you have knock retard or not.

Agreed, but my concern is more about GM's warranty, not the small amount of HP loss due to retarded timing. The retarded timing is probably the cause of the misnomer that premium fuel has more power than regular.

Some interesting info here: http://www.faqs.org/faqs/autos/gasoline-faq/part3/

However it does not address knock sensors, atmospheric perssures, etc. but does offer some good information on gasoline.

This post has been edited by 35th_Anniversary_AS_Camaro_SS: Dec 15 2005, 12:02 AM

[CMC#5]

hehe so then why is the max octane in Ca 91 not 93? :leaving:

[trackbird]

hehe so then why is the max octane in Ca 91 not 93? :leaving:

As I remember, high compression will raise your NOx (oxides of nitrogen) emissions levels. So, by limiting fuel type, they could be trying to limit compression ratios.

Maybe?

[35th_Anniversary...]

I was thinking it could be something about emissions as well. But higher compression ratios are more efficient. So who really knows what the reason is there.

[trackbird]

I was thinking it could be something about emissions as well. But higher compression ratios are more efficient. So who really knows what the reason is there.

They are more effecient, but they raise the NOx output of the engine. So, being California, they may be choosing between fuel consumption (which has road taxes in it, so more is better) and emissions (of which they are the emissions nazi's).

But again, that's just a guess and I may be completely wrong.

[CMC#5]

So you think the CARB (Cal Air Resource Board) is attempting to limit the compression ratio auto manufacturers choose by limiting the octane of available fuel in this gigantor market? Its plausible. I really don't know why the specifications are what they are, I just know there are a pile of different and sometimes conflicting specs that refiners have to meet. At the end of the day I know one thing...it results in gasoline being more expensive than it could be. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/dry.gif)

[trackbird]

So you think the CARB (Cal Air Resource Board) is attempting to limit the compression ratio auto manufacturers choose by limiting the octane of available fuel in this gigantor market?

I don't know. It was just a theory from the thinking out loud file. It's not like Colorado where they have altitude to negate the need for it. So, it makes me wonder if they are worried about NOX and compression ratios. I could be crazy, or I might be right. I'd love to know for sure.