Interesting - sorry the distribs didn't cure your issue.

The manual states the minimum continual use at Premium grade RON-95 (min 91 for short periods) and so I would suspect you'll run the risk of damaging the engine on anything less.

__________________
'93 R129 500SL-32
'89 190E 2.6 - sold in 2002

http://antron.pwp.blueyonder.co.uk/i...nature/Sig.jpg