[Joakim]

I have heard that the Porsche engine needs to run with the 99 octane(or was it this or less, can't remember) fuel that the 95(e10 octane and 98(e5 octane fuel does not include some thing that are good for the valves.? Is this right?

My 924 is basically family car, my parents bringed it from Sweden to Finland when they moved in the mid eighties..

My father said that the valves has been changed for in sometime in the 924's life, that it can handle the 98 octane fuel too without the additive..

Is the real name for the additive octane raiser?