Research Octane / Motor Octane ?

[Merkava_4]

Difference between the two ? Which one is on the gas pump ?

LINK

 

[Shannow]

 

[javacontour]

Says on the pump, US uses (RON+MON)/2

Also known as the AKI or Anti-Knock Index.

 

[4WD]

AutoExpert ? He did the Ute review posted a while back ?

 

[Nyogtha]

http://www.zeltex.com/eval.html

In US pump octane is listed as the average (R +M)/2 shown on the sticker on the pump.

Outside the US often only the Research octane number is listed.

There are minimum motor octane number specs in the US in addition to the minimum (R+M)/2 number specs.

 

[Vern_in_IL]

...and 10% ethanol is added, making low quality 85 now a 87 E10.