seems there is a secret society to which these chosen techs belong. Testing the RS6 with octane boost in premium gas produces "awesome power".

I might give one tank of gas a try but I'm not going to make the autoparts store a regular part of my rounds.

Anybody tried boosting their pump gas yet?

Those octane boosters don't do anything. You're better off just using a higher octane gasoline.

And what does that equate to in English please?

Premium unleaded here is 95 RON, "Super unleaded" is 97 RON and Shell Optimax is over 98 RON (98.6 I've seen).

is measured as RON+MON/2.

My limited knowledge shows RON to be 8-10 points higher than RON+MON/2.
BMW says a 91 RON should equate to 82 MON.

So your petrol would be approximately 86, 88, 89 R+M/2 in the US.

I see 87, 89, 92 R+M/2 here on the pumps I use.
Other states have a max of 91 (California?) and some go beyond 93.

That being the 100 that we don't even get yet in Britain. Shell sell "V-Power" 100 RON in mainland Europe, but it hasn't hit UK shores yes, nor might it - Shell probably don't make any money on Optimax as it is, so I doubt they'd bring something even more expensive over.

I wouldn't bother with the octane booster, your 89 and 92 should be fine, but stick with one or the other as the ECU's timing advance is supposed to take a lot longer than retardation if it detects any knock/pinking - a single tank of 92 wouldn't do a lot of good after several tanks of 89, and swapping the other way would probably cause retardation almost immediately.

I wouldn't run 87 - over here running the engine hard on 95 RON fuel is warned against in the manual.

although I don't have any info to back that up.
I guess I'll make the 30 minute drive to fill my tank with 100 octane at the pump.

I'll have to check.

is only 2 miles from my house!

A 30 minute drive for good petrol is just what my checkbook needs.

Did the 100 octane make a difference on the S6 butt dyno?

<ul><li><a href="http://www.vtr.org/maintain/gasoline-octane.html">click</a></li></ul>

I bought my house a year ago.

I had in my old S4 and thought I felt a little better. Not worth the $4+ per gal better but...

Figured it wouldn't be worth it in the S6.

Unless you have a 100 octane program on w/e chip you're running, it won't make much of a difference. Resetting the ECU before filling up will help on a stock chip but otherwise your ECU has already gotten used to "normal" premium gas.