gas type?

93 octane.

if you read the manual i believe it says... 90 is sufficient...though it might say 91 i only use premium b/c u can tell the difference there's a lot of engine ping with the lesser gas

The owners manual states to use 91 octane or higher. I would reccomend 93 octane, especially in summer months. The only way I would run a lower grade is if you had extensive knowledge about altering your spark timing tables safely.

Gas type in a 2007 grand prix