From: kludge@panix.com   
      
   AK   wrote:   
   >My 2009 mazda cx7 recommends premium grade gas.   
   >   
   >I have been using mid grade for about 5 years with no issues.   
   >   
   >I get the advertised gas mileage. 20/28 city highway.   
   >   
   >Is my car retarding the timing by that?   
      
   Put it on a scanner and see.  If you're not driving aggressively, it might   
   not be.  If you're driving aggressively, it might be.   
      
   >I read where that can causing knocking.   
      
   No, the computer system will retard the timing to prevent that from happening.   
   It's not like the engines of the seventies where you could damage them by   
   using too low octane fuel.  Now all you lose is performance when the system   
   pulls the timing back.   
      
   >Wondering if regular gas would work.   
      
   Maybe, try it.  It won't hurt anything.  It might not accelerate so well,   
   but that might not bother you.  Or maybe it will.  Try it.   
   --scott   
      
   --   
   "C'est un Nagra. C'est suisse, et tres, tres precis."   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)