Because stock, especially on the 140hp 1.8T's there is enough reserve to run higher charge pressure in case of lower octane fuel to compensate for ignition angle inefficiency, thus retaining the same power with 95 RON as with 98 RON.
On many stock cars the second map is never used, because the switchover is disabled.
Hi prj!
Your thoughts are absolutely logical! Thanks a lot for your explanation!
Could you explain which switchover you meant?
