What Octane Rating Do You Guys in The U.S Have?

[MARKTHOMASBRAND]

Hi,
Just wondering what the octane rating is in the U.S of your unleaded fuel.
In the U.K regular unleaded is 95 Octane and super-unleaded is 97 Octane.
All the best,Mark.

[2000GTP]

91 and 93 is the premium grade around here.

[Injuneer]

You can't compare the pump posted octane number in the US to those posted in Europe. Europe uses a different octane rating for posting on its pumps, compared to the US. Europe posts "research" octane. US posts the average of "research" and "motor" octane..... or (R+M)/2

Research octane is a measure of the fuel's ability to resist detonation, as measured through a test routine that most closely simulates "normal" driving... part load operation. Motor octane is measured using a a test routine that more closely resembles high load operation, or what you get when you push the engine to max load/WOT. Research octane can be anywhere from 5 to 10 octane numbers less than Motor octane.

Octane requirement is also heavily affected by altitude, so you may find US fuels rated at 93-octane (R+M)/2 as sea level, and fuels rated at less than 90-octane in Denver, where the altitude precludes the necessity of any higher octane.

Good reference on gasoline:

http://www.faqs.org/faqs/autos/gasoline-faq/part1/