Re: MPG and Octane

[kohlbren-m-d@xxxxxxx]

John Firestone wrote:

> Back in the days when the middle 'M' stood more for Motor than
> Marketing, German BMW brochures included a few sentences like the
> following [my translation from the Fall 93 E36 coupe brochure]:
> 
>    Engines with knock control are designed for RON 95 fuel.  If
>    RON 98 is used, the standard fuel consumption will decrease
>    by roughly 1% and engine power will rise.  With RON 91, fuel
>    consumption will increase by roughly 3% and engine power will
>    fall.
> 
> At that time and I expect now, the increased fuel consumption largely
> erased any expected savings of using regular unleaded (RON 91) fuel.

Does anyone have any idea as to how applicable this information is
to the M30 engine in my '92 535i (I think it has Motronic 1.3...)?

Does my engine even have a knock sensor?

The recommended minimum octane (R+M/2) is 87 and it runs just fine
on that.

Regards,
Mike Kohlbrenner

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