I'm having an argument with my mate who is an ECU reprogrammer.

He says I should use Super+ unleaded in it, I say 95 octane is fine, that's what it says in the handbook...




I do get occasional light engine knock on light throttle in a high gear with 95....

If you do use Super+, have you noticed any difference, and do you use 97 or 99 octane...

 Pete

__________________________________________________
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-

I use Momentum 99 in my 4.2 SC and am approaching 170,000m. When the spark plugs were changed at the recommended 110,000m they looked like they had only done a few thousand miles & didn’t need changing, so I’ve kept the old ones as spares just in case.

I think it’s well worth the extra few pence a litre

Always use use Shell V-Power Premium in my 4.2 SC , never used anything else so cant compare.

NB: The mower seems to like it as well.

TBH honest, I use both.
That's partly because I either forget or end up at a pump that doesn't have!!
My Audi TT used to play up if I didn't put in the higher octane fuel in it but to date, with the SC, I haven't really noticed a difference! 2005 FFRR SC Java Black with Overfinch Exhaust (UK)
2008 D3 HSE Stornoway Grey (UK)
2008 D3 HSE Izmir Blue (ZA/Zimbabwe)
1995 D1 300 Tdi (Zimbabwe)

Tesco cheepest all the way pete

I’ve only covered 1k so far in my 5.0 SC, but have been running it exclusively on V-power.
An ECU should adjust according to the quality of the fuel, so 95 will be fine - but I choose to run super so the ECU doesn’t dial anything back (and also for the additives that hopefully keep valves cleaner etc).

I ran a Subaru Legacy 3.0 for 10 years previously - super or normal made no difference whatsoever, but it was a normally aspirated engine. I also have a 200SX which hates normal unleaded (down on power and mpg) but admittedly that is mapped to V-power so is perhaps not a reliable witness

My thinking is super probably benefits forced induction engines more...?

Thanks guys... seems to be quick enough on 95 octane for me, I saw some super + the other day at 30p per ltr more than 95....!!! £30 extra a tankful doesn't seem worth it to me.....  Pete

__________________________________________________
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-

Shell Super in both mine

V-Power for me. Its one of those marginal things - its probably tiny, but the engine will be faster with better fuel. If that wasn't important to me I wouldn't have the most powerful version available. Seems daft to spend a fortune on buying the highest potential then reigning it in to save a few £ at the pumps. Noted that some garages take the pish and have a huge differential...but most are around 12p/liter so maybe a tenner per fill from empty. Also agree above about some value in the extra additives/cleaners although only likely to make a difference over a longer period of ownership. Its been good in my other cars even from Optimax days and I've had one of them over 30 years another over 18 etc.. Mike - MPx

2017 5.0 V8 Supercharged SVAutobigraphy Dynamic SVO Palette Grey (2021-...)
2012 5.0 V8 Supercharged Autoboigraphy Orkney Grey (2017-2021)
2007 4.2 V8 Supercharged Vogue SE Tonga Green (2012-2017)
2002 4.4 V8 Vogue Bonnatti Grey (2008-2012)

20k miles since I bought it and always use regular unleaded. Drives like a dream and plenty of go.

If regular was good enough for my 911, it's good enough for the S/c. 2017 5.0 Autobiography Supercharged
2005 Merc SL350
2005 Disco HSE 2.7 oil burner

Super+ only...Preferably Shell V-Power...I used it currently in the 5.0SC, the M2c and the old MK2 GTI. Same as in the AMG's we've had. And the Golf R that I used to race was terrible on lower grade, heck couldn't even trust Tesco Momentum due to lack of consistency.

Super+ Shell V-Power all the way...

Sainsbury's bog standard is good enough for me🙂. Used it for the last 8 years and 40,000 miles. 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

Super and V Power for mine

Regular 95 octane for my 4.2 SC and there’s never been a hint of pinking.

I may well end up using V-Power or similar just to avoid the extra ethanol they’re going to start slapping into regular petrol. 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)

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.....!! Pete

__________________________________________________
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-