USE OPTIMAX BOYS !!!
The cleaning agents in this stuff are far better than any other fuel - and don't put one tank in expecting miracles either! If you use it consitantly you see the benefits ...
On my MKII 8v GTI it says to only use RON 98 ...
The main reason for alot of speculation about this is for an engine to 'adapt' to it's fuel it has to have a knock sensor to give it the ability to adjust the timing for a higher RON rating. Not sure what Golf's do or don't have this this ... GTi's do
If you ran 2 engines - one on Optimax and one on Super and strip the block the difference inside is amazing ... Optimax definaltely does the job.
Dave