F-Body Europe

Which octane fuel is everyone running?

Super Premium. I wouldn't run anything else in our cars. The small difference in price is not worth the risk of burning up a piston from detonation.

I've been running the 98 that they have here on base....I was just curious about everyone else.

95 ... I tried the 100 stuff once, and couldn't notice any difference on the track ... neither on the time/performance, nor on the logs (knock etc.) This might of course be caused by the fact that I did my Speed Density tune while running on 95 ...

95 (Super) like Garry. Ran 98 for about a year or so. No difference whatsoever (also made measurements, data logging, Bitburg runs) except for worse fuel consumption.

I may try 95 just to save a little money...my tune was done on 93 anyways. Is there a difference in the octane from the states to here?

Yes, there is a difference. I'm not sure exactly what it is. I'll stick with the super premium. Years ago, I had to replace a couple of pistons and that is no fun so I'll stick with what I know works. Also, you will normally get better gas mileage from the higher octane so that helps reduce the difference in price.

If you figure 28 mpg, and a price of $2.80 per gallon for super premium as opposed to $2.60 for super, the price difference for 50,000 miles is about $500. If you melt the top out of a piston, you'll spend a lot more than that.

Don't confuse European octane with US octane. US 93 is like European 98.

KC10A:
Super Plus has a slightly lower energy content (Energiegehalt) compared to Super, that is -- I think -- why I experienced worse fuel consumption with Super Plus.

My 2cent's worth (I used to work in engine design when I was younger).
If your motor (assumed you left it stock) was designed to run on say 93 octane, then it would not make one bit of difference (improvement-wise) if you use 98, 100 or 200 octane. Octane does not make more power, it's there to deal with higher compression (which makes power).
Roughly how it works.... the lower the octane, the more violent the fuel ignites (as in exploding!). When you have a high-compression motor and the low octane fuel explodes, the shock (knock) will eventually destroy your pistons / big end bearings. Therefore you use higher octane, slower burning fuel that will add a more progressive pressure build-up on the pistons instead of slamming them down with a big hammer action.