27 Apr 2005, 07:39, TOM WALKER (1:123/140), wrote to MATT MC_CARTHY:

Hi TOM.

 MM>>You _might_.  Modern engines have anti-knock sensors built into 
 MM>>the engine block to 'listen' for detonation and retard the spark 
 MM>>timing accordingly.  I by using a higher octane fuel the anti-knock 
 MM>>sensor fails to 'hear' detonati then your onboard computer may let 
 MM>>the engine run at a higher timing advance which would improve your 
 MM>>mileage.  Even one or two degrees additional timing advance should 
 MM>>give you improved mileage in the range you seek.

 TW>  ONLY if there was some problem with the Engine itslef. Like bad 
 TW> timing

I don't think so.  Most car timing is now completely automated, and is set
by the computer to two degrees below the 'knock point', where ever that
happens to be.  A higher octane will then raise the 'knock point', and thus
the timing will run more advanced.


     Good luck...  M.

--- Msged/386 TE 06 (pre)