E46 330ise petrol grades

[Robmilford]

I have owned my 330i se touring for just over a week and on reading the hand book it sayes that it can be run on 98 Ron or 95 Ron petrol and only in emergancys on 91 Ron. I thought that all premium unleaded was 95 Ron and super unleaded was 98 Ron, but some garage pumps do not state the grade. Does any one know what the 91 Ron is labled up as so I can avoid it and is it worth using the super unleaded (98).

[baz1985]

V-Power all the way mate

[JonRB]

Standard unleaded ("Premium" strangely) in the UK is 95RON and Super Unleaded is a minimum of 97RON but can be higher.

You can't get anything lower than 95RON in the UK, not that I am aware anyway.

Finally, the 330i SE runs very happily on 95RON - that's what my wife runs her 330i SE Sport Touring on and it doesn't complain.

(Edited to correct a typo)

Edited by JonRB on Tuesday 27th February 09:23

[dcb]

Robmilford said:

I have owned my 330i se touring for just over a week and on reading the hand book it sayes that it can be run on 98 Ron or 95 Ron petrol and only in emergancys on 91 Ron. I thought that all premium unleaded was 95 Ron and super unleaded was 98 Ron, but some garage pumps do not state the grade. Does any one know what the 91 Ron is labled up as so I can avoid it and is it worth using the super unleaded (98).

You can't buy 91 RON in the UK, AFAIK.
I suspect you can't buy it anywhere in Europe.

The only country I've ever heard that sells 91 RON is Mexico.

Ordinary UK petrol is 95 ron. Your BMW should run fine on it.

It will make the book specs on 98 RON. If your BMW is anything
like my 530, it will absolutely *love* 100 RON or more.

Much smoother running, and higher top speed.
Handy near Cologne.

[rassi]

dcb said:

Robmilford said:

I have owned my 330i se touring for just over a week and on reading the hand book it sayes that it can be run on 98 Ron or 95 Ron petrol and only in emergancys on 91 Ron. I thought that all premium unleaded was 95 Ron and super unleaded was 98 Ron, but some garage pumps do not state the grade. Does any one know what the 91 Ron is labled up as so I can avoid it and is it worth using the super unleaded (98).

You can't buy 91 RON in the UK, AFAIK.
I suspect you can't buy it anywhere in Europe.

The only country I've ever heard that sells 91 RON is Mexico.

91 RON is sold in almost all German gas stations, with "Super" being 95 RON and "Super Plus" 98 RON or even 99 or 100 RON.

[dcb]

rassi said:

91 RON is sold in almost all German gas stations, with "Super" being 95 RON and "Super Plus" 98 RON or even 99 or 100 RON.

Surprising - I've never noticed 91 octane anywhere in
Germany. Maybe I need to look closer next time.

I was having a chat with a petrol station attendant,
and he reckons that 98 RON is mostly history
in Germany.

Customers are buying 100 RON in preference
to the 98 RON, leading to the petrol companies
not selling 98 RON anymore.

[Onetone]

And remember: all petrol starts to degrade after a few days - fill your car with 98/100 ron and, after a week, it will be down to nearer 95 ron anyway. Super unleaded is a total rip-off unless you buy it as soon as the garage has taken delivery of it and then use it all straight away.

[daver]

Sadly, a tank doesn't last for anything like a week for me.

Not being a petrochems expert, why does this degradation occur?

I thought I heard once that the octane rating on things like Otimax/V-Power was a sort of frig anyway that was liberated by small amounts of "something" that was added at the pump as you filled your tank. Is this true - or is that just the detergent elements that those fuels (claim to) have?

[JonRB]

daver said:

Not being a petrochems expert, why does this degradation occur?

Because petrol is volatile, presumably.