UK super & normal unleaded?

[chazno5]

Silly question,

But has any UK Beemer drivers noticed their cars driving quite different if you use super unleaded (97octane) or normal unleaded (95octane). Obviously your car feels quicker and zippier with the super unleaded, but I have noticed that after filling up with some super after I have been using normal unleaded for a while, my car idles a little slower just for a second? Also at very low revs (below 1300 rpm) my beemer seems to feel a little hesitant and not so smooth? Once above 2000 rpm my car feels pretty lively though.

When I then later in the week fill up with normal unleaded my beemer actually seems to idle much more smoothly and pulls away from low revs much more smoothly, even a bit quicker as well? Except of course once I am cruising at above 2000 rpm my beemer does not feel quite so lively on normal unleaded.

Can anyone answer why more beemer's engine seems to respond differently at different revs on the two petrols?

Thanks.

[vwk]

I'd prefer the 98 above 95, and yes I more or less feel the same as you. Only difference in Holland it's 95 and 98, so a bit more difference in the advantages of 95

Filled it up with octan 100 in germany once, that was a real fun to drive

[chazno5]

Hi,

Thanks for the reply. Yes I have heard that Holland and Germany have 98 super unleaded, as opposed to the UK's 97 ron. I have sometimes seen BP petrol stations selling 98 ron, but not very often.

Thanks,
Charlie

[zeaq328i]

I use Ron 97 Unleaded(Brunei) which is recommended for my Beamer.The higher the octane, the fuel is cleaner...

By the way i heard UK Fuel has sulphur. 328i and 528i with nikasil engine are affected.