I also use Sta-bil, have for about 15 years. And as far as fuel octane, I use mid-grade which here is about 87 octane.
Also, here is an interesting article on storing a vehicle.
http://history.gmheritagecenter.com/wiki/index.php/Long_Term_Vehicle_Storage"To avoid engine bearing damage due to acid in the engine oil, change the engine oil and oil filter. Drive or run the vehicle until the engine is fully warmed up. This will remove moisture from the exhaust system, circulate the new engine oil, and remove any moisture that has accumulated in the crankcase due to cold engine operation after start up. If not practical to drive the vehicle, then allow the engine to run until fully warmed up, then 1 (one) hour more. After shutting off the engine at the end of this procedure, do not start the engine again until the vehicle will be driven and the engine oil is brought up to normal operating temperature. Starting and stopping the engine without bringing the engine oil to normal operating temperature will cause moisture to contaminate the engine oil." I read a similar article about 4 years ago. Since then I fill up the gas tank, add the fuel stabilizer, drive the vehicle, change the oil, hook up the battery trickle charger, add some dryer sheets inside the vehicle - under the hood and on the floor (keeps mice out), put the car / truck cover on it and leave it as is until next spring. I no longer periodically start the vehicle.
I will say though that before I read the article I also started the engine about once a month and let it idle until it reached operating temp, then shut it off and covered the vehicle back up. I never experienced any problems... but the article made sense to me, so I changed my storage routine, for what it's worth.
Hope this helps.
