87 dude, period.
You only run above 87 if you run a supercharger,turbo or nitrous
, or other custom setup which alters your engine timing....thus requires higher octane.
There are some regular cars out there that require above 87....i believe some BMW's, Mercedes and mostly imports.
You NEED to read the users manual, it will tell you 87 octane.
Using above 87 on your stock motor IS A WASTE OF MONEY.
It won't burn any cleaner, the point of higher octane is to spread the fuel molecules farther apart, so it burns slower on motors that require it.
You can damage your motor with higher octane gas by excessive engine "pinging", so if you've been getting pinging, STOP using higher octane...(you shouldn't be using it anyways)