Fuel in the US.............

[Muzzle of Bees]

The price is in constant flux, up or down ~ .15 cents during the year here in Texas. Right now 93 Octane is about $3.78/gallon.

[BIGJake111]

93 octane for about $3.50 a gallon

[SKOOSH1970]

Any problems with detonation running 93 RON fuel....?

[pjq]

good topic.
The best octane rating you can buy in eastern canada is 91 octane, cost now $1.41/ltr.
In eastern USA (Maine, NH, Vermont maybe even Mass.) the best octane is the same 91 octane.
1 year ago in Quebec, the best octane you could buy was 91 except around the Montreal and Eastern Township area some gas stations(Petro Canada) sold 93 octane.
I recall in the Mid to southern USA I could buy the 93 octane.

So, makes you wonder when your gas cap is asking for 97-98 and all you can give it is 91??? But the car seems to run ok. I'd really like to try the 97-98 to see if there is a difference.

[SKOOSH1970]

Wow, really surprised you guys don't add octane booster if all you can buy is 91 RON fuel..... I used to run high powered Subaru impreza's years ago..... even added octane booster to 98 Ron fuel then to avoid detonation which still used to spike occasionally on the knocklink..............!!!

Just goes to show how misguided drivers are generally around the world I guess...( by car manufacturers )

[Ian c]

Indeed they are misguided .
Misguided into thinking the Ron system in America is the same as it is in the uk .......

[mump]

Originally Posted by SKOOSH1970

Wow, really surprised you guys don't add octane booster if all you can buy is 91 RON fuel..... I used to run high powered Subaru impreza's years ago..... even added octane booster to 98 Ron fuel then to avoid detonation which still used to spike occasionally on the knocklink..............!!!

Just goes to show how misguided drivers are generally around the world I guess...( by car manufacturers )

Remember, when we in the US are saying 93 octane, it is 93 AKI = 98 RON. 91 = 95 RON.

[Deserion]

Originally Posted by pjq

So, makes you wonder when your gas cap is asking for 97-98 and all you can give it is 91??? But the car seems to run ok. I'd really like to try the 97-98 to see if there is a difference.

The 97-98 is measured in RON, whereas in North America we use AKI which is also labeled as R+M/2 on the station pumps. Basically, take RON and multiply by .95 and you'll get the approximate AKI number. 98 RON = 93 AKI, 94 RON = 89 AKI, 92 RON = 87 AKI.

As far as I'm aware the 986 needs 95 RON as a minimum, which roughly correlates to our 91 AKI.

Also makes sense why most direct European engines need 91+ AKI to run right in North America, while NA-specific regular engines are designed to run 87+ AKI. My E320 specifies premium, as does my housemate's Mini Cooper.