Is lower octane better at higher elevations?

A: At higher altitudes, the air is thinner so you can actually get by with a lower octane gasoline. For instance, regular grade fuel is 87 octane in Chicago, but 85 octane in Denver. Your car will adjust itself for any elevation.

Why is Colorado gas lower octane?

According to this article from AAA, the stated reason is that most of Colorado is at high elevation, above 5000 feet (about 1500 meters), and the thinner air tends to prevent detonation. Therefore, in theory, one can use the cheaper, lower octane fuel without problems, and save some money.

Why does Utah sell 85 octane gas?

He explained the air is less dense at Utah elevations than at lower altitudes, which means the engine draws in less air during combustion. Up here, 85-octane is just fine for most cars. He said using 85-octane at higher elevations naturally deters the pre-ignition or knock, that 87-octane does at lower elevations.

How does altitude affect octane?

In some high-altitude areas, you’ll find 86 or even 85 octane gasoline sold as “regular” grade. At higher altitudes, the thinner air compensates for the gasoline’s lower octane, so the engine can usually run without detonation.

Do you need high octane gas in high altitude?

Octane Ratings At Altitude Because the air is less dense, less air flows to your car’s engine. This translates to a slightly richer air-fuel ratio, and deters engine knock. In most cases, you won’t experience any problems running 85 octane in an ordinary car when a few thousand feet above sea level.

Why are octane levels lower?

Octane is an index number that measures a gasoline’s ability to resist engine knocking. American refineries produce gasoline with octane levels ranging from 85 to 94. The lower the octane level in gasoline, the less expensive it is for refiners to produce.

Why do some states not have 93 octane?

Supposedly, CARB was concerned about the emissions at the refineries, so they coordinated all of the oil companies to stop offering >91 octane together (so that no one oil company would use 92, 93, etc. as a marketing advantage to gullible consumers and therefore dissuade other oil companies from going to at most 91).

What octane is high altitude?

Why does Colorado use 85 octane gas?

Octane Ratings At Altitude Because the air is less dense, less air flows to your car’s engine. This translates to a slightly richer air-fuel ratio, and deters engine knock. For that reason, you’ll find that regular gas carries an 85 octane rating here in Denver and throughout Colorado, Wyoming, Utah and Montana.

What does higher octane fuel do?

Higher octane allows engines to have higher compression ratios (for a more energetic explosion), more advanced ignition timing or forced-air induction like turbochargers or superchargers. It’s the fuel’s ability to be compressed more without pre-igniting that results in more power when used in the appropriate engine.

Why does California only sell 91 octane?

Because only a certain percentage of a barrel of oil can be refined into higher octane gas, and California has a higher ratio of cars requiring high octane fuel.

Why do Western states only have 91 octane?

Vehicle emissions are basically unchanged with varying octane as long as it’s above the minimum recommended, and the method used to raise octane isn’t in itself damaging such as tetraethyl lead. This is why 91 is common all over the west – the refineries are in California.