I haven't experienced any pings or knocking using Shell Gas.

Here's a link to Top Tier Gasoline site which cites benefits of using brands which adhere to its principles - unsure of affiliation so be aware this is probably biased.

http://www.toptiergas.com/index.html

Try Shell or another National Brand next fill-up, still using 87...

Tom

07 TCH Blue Ribbon Metallic / Ash - w/ light blue/yellow pinstripe
Options: Leather, Moonroof, Nav., C&C package
Added -Toyota: Rear Spoiler, Body Side Molding, Rear Bumper Applique, Camry Mats, Door Sill Enhancements
Added-Other: Sirius Starmate4, BilletAmerica Mirror Chrome Pillars; Color-Keyed Mud Guards



HSD Community Reason #12439
http://www.toyota.com/vehicles/minis...ids/index.html

Wife's whip - 07 Pontiac G6 GT Convertible - Crimson Red / Light Taupe