From: scientist77017@gmail.com   
      
   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?   
      
   I read where that can causing knocking.   
      
   Wondering if regular gas would work.   
      
   The price used to be only about 30 cents more to upgrade to midgrade.   
      
   That is no longer the case.   
   Thanks,   
                  Andy   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)