Originally Posted by 328i M-Sport
The problem with their test was that the car looked pretty new. Of course, a new Chevy Cruize will run the best on regular as designed.
As cars get old, especially if they were driven by grandmas and never taken above 2500 rpms, carbon deposits will get inside combustion chambers. Smaller (effective) combustion chambers will act the same way as the engine with a higher compression. And a car that always ran well on regular can start pinging. Direct injected engines create carbon deposits a lot quicker than regular SFI cars.
There are services like MotorVac that can help with the problem but a higher octane gas will work as well.
Back in about 1982 my New Monte Carlo used to ping on occasion so I would fill up with "premium" and the pinging would stop. Like the Cruze, All modern day engines have systems to prevent an engine from ping