In my experience, with a supercharged Chevy LS2 engine, there was a very noticeable difference when on the odd occasion I had to run it on 95 RON petrol.

Admittedly, that is a far simpler engine and it and the Vortech SC had been mapped to 98 RON petrol.

If you want reassurance, throw some Red X (other brands are available) in, every now and then. Or, if you really like throwing money away, go for the Terraclean! Previous cars:
S-Max 2007-2013 (only diesel I've had, good car but expensive when diesely bits go wrong, so what's the point?)
Galaxy 2001-2007
Mondeo Estate 1997-2001
Sierra Estate 1993-1997
Uno Turbo 1987 -1993
Fiesta 1984 - 1987
Fiat 127 1982 - 1984

Well this is obviously a Marmite scenario.... a bit similar to should you do a power flush on the gearbox.... or, should you only use genuine parts... (and lets not examine those thoughts on here...!!!)

I suppose we are all different, have different ideas and thoughts and as long as we are individually happy with our own decisions then that's all that matters...

Our fatty's will run on 95, or even less, and also use 99 with no detrimental effects...

So, pay your money and take your choice...  Pete

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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Haylands wrote:

Interestingly the largest market for the S/C, the USA, has the worst petrol, they have Regular at 87, Midgrade from 89-90 and Premium from 91-94 so even their top octane is lower than our standard petrol.....!!