Originally Posted by BestTimesNow
The octane can be lower in Denver because of the altitude.
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Octane ratings can vary greatly from region to region. For example, the minimum octane rating available in much of the United States is 87 AKI and the highest is 93. However this does not mean that the gas is different.
In the Rocky Mountain (high altitude) states, 85 octane is the minimum octane and 91 is the maximum octane available in fuel. The reason for this is that in higher-altitude areas, a typical combustion engine draws in less air per cycle due to the reduced density of the atmosphere. This directly translates to reduced absolute compression in the cylinder, therefore deterring knock.
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http://en.wikipedia.org/wiki/Octane_rating
cool, i didnt know that. i still wish we had your pump prices though and your car prices.