Substitute Reg for Prem? Re: OT: Oil companies

[rocco16 at sbcglobal.net (LEF)]

  For our "other" vehicles - reducing fuel costs. I've heard that reg gas 
  can be used in place of prem gas for "recently" manufactured cars (that 
  were designed for prem) because the ECU will make all necessary 
  adjustments. T or F ?

  *********
  True, to a point.  Modern ECU's can retard timing if they detect detonation.
  Modern, well-designed heads can get by  with higher compression and still use low octane (91 and below) fuel because they controll the 'burn' much better than the heads of thirty years ago.  
     Cams with lots of overlap tend to "bleed" off compression a bit, allowing an otherwise high compression engine to have, in actuality, lower compression.  An ECU will not affect valve timing in response to detonation.
  Not just 10 year old cars can compensate for lower octane fuel; the 16v Sciroccos (which are right at 20 years old these days) had that capability.

  I always run premium in my 'Roc....the extra 10 or 20 cents a gallon ($2 on a fill-up) is not enough to concern me.

  larry
  sandiego16v