Unleaded Fuel, Did the 914/6 2.0 use Leaded Fuel? Options

[Jeffs9146]

As it says above, does the original 2.0 914/6 use leaded fuel or is unleaded ok? The book says 98 octain but it doesn't say anything about Leaded or Unleaded. My 74 had an Unleaded Only sticker but the 6 doesn't!

Jeff

[ArtechnikA]

European is ROZ/RON where as American is (R+M)/2.

... a stock engine (4 cylinder, I don't have a six so I don't know sixes) shouldn't require any a higher than 87 octane rating.

"ROZ / RON" is not a method, it's just bilingual -- Research Octane Zeitung / Research Octane Number (same thing...). don't know what method the Europeans are using today (Jeroen ?) but the Research number was typically used in the early 70's -- it tends to produce a higher number for the same fuel and therefore the petroleum companiues liked it -- but the auto industry and "consumer groups" claimed the Motor number was closer to what an operating engine actually required. as a compromise, the number you now see posted is the average of the Motor and Research numbers. this change was mandated by Fedral law somewhere in the early 80's IIRC.

1,7's had a slightly higher static compression ratio and can use midgrade. the /6 owner's manual calls for premium. "should" it need it ? maybe not, and i don't recall any pre-ignition issues, but i'm not risking it nowadays with the 911 ...