Subject: depends on the engine Author: shogun (moderator) : member since March, 2004 : 16005 posts Posted on: 2010-02-15 21:54:01

if no no knock sensor, engine will not recognize it like the M30 and M70 engine, M60 has.
The octane rating of a given grade of gasoline is a measure of its detonation resistance. The higher the octane number, the better able the fuel is to resist detonation. Most engines in good condition will run fine on regular grade 87 octane fuel. But engines with high compression ratios (over 9:1), turbochargers, superchargers, or with accumulated carbon deposits in the combustion chamber may require 89 or higher octane fuel.
How a vehicle is used can also affect its octane requirements. If a vehicle is used for towing or some other application where the engine is forced to work hard under load, a higher octane fuel may be necessary. Anything that increases normal combustion temperatures or pressures, leans out the air/fuel mixture, or causes the engine to run hotter than normal can cause detonation.
Carbon deposits can often be removed from an engine that's still in service by using a chemical "top cleaner." This type of product is poured into an idling engine through the carburetor or throttle body. The engine is then shut off so the solvent can soak into and loosen the deposits. When the engine is restarted the deposits are blown out of the combustion chamber.
In many European countries, and other countries such as Australia, the octane rating used is called the Research Octane Number (RON). These octane ratings reflect how the fuel acts in the lab. In the U. S., however, as well as a few other countries, the octane rating is called (R+M)/2. This number is derived from the average of the RON and the Motor Octane Number (MON). While the first rating is determined by the fuel’s performance in the lab, the MON is supposed to reflect how it performs "out in the real world." Therefore, an average of the two numbers should theoretically give the best indication of the fuel’s burning characteristics.

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E32 750iL 11/88, E32 750iL Highline 03/90
SHOGUN'S TRICKS AND TIPS FOR THE SEVEN SERIES

• OCTANE USE SURVEY - kemco 2010-02-09 14:54:44 (690 views)
  • one more hint though... (url) - bcweir750 2010-03-22 21:45:13 (554 views)
  • I used 87 octane nearly all the time. - bcweir750 2010-03-22 21:42:52 (667 views)
  • Re: OCTANE USE SURVEY - dbogdan 2010-03-22 16:44:35 (550 views)
  • depends on the engine - shogun 2010-02-15 21:54:01 (690 views)
  • Re: OCTANE USE SURVEY - paulmer 2010-02-10 16:51:59 (654 views)