Super unleaded

[strummer]

I always run my X5 on normal unleaded but just put some 97 octane in and it definately feels better,any thoughts on this,mpg etc?

[X5Sport]

The difference in cost per litre isn't worth it.  Same with the Super Diesel.  Unless your vehicle really needs it - and most don't - you are doing no more than emptying your bank faster.

[AW8]

I reckon that I get around 10% improvement in mpg so for me if it's more than 10% dearer per litre it's not worthwhile.

Car gives best mpg when up to temp.

Incidentally mine seemingly runs best on 97 octane as opposed to 99 octane. I think engine runs best 95-97 according to literature and sticker in fuel lid.

I reckon additives may help engine care too albeit more benefit probably by me generally keeping revs sensible when cold.

Placibo effect probably a factor too

[shadrack]

i think my ml63 runs on 98 oct better in mpg but as said above the last time i looked there was 23ppl differeance near me, so i just put standard in, on my cap it says recommended 98ron, min 93ron so i pressume standard 95ron is fine

[saucysimon1954]

[quote="shadrack"]
i think my ml63 runs on 98 oct better in mpg but as said above the last time i looked there was 23ppl differeance near me, so i just put standard in, on my cap it says recommended 98ron, min 93ron so i pressume standard 95ron is fine
[/quote]

95 only if 98+ isn't available.