If you open the gas lid...it says "PREMIUM UNLEADED FUEL ONLY
well atleast mine does

1 for regular and 1 for premium. The mid-grade gas is a 50-50 blend of the two.

I'm not sure this is correct.

it varies.

http://www.edmunds.com/advice/fuelec...3/article.html

Just enough octane rating to prevent detonation in your driving. For normal use, go 89 at cold temperatures and 91 when warm. Lots of hills or lugging around a lot of cargo, go with 91 or better.

More octane beyond whats needed is useless and a waste of money, unless your engine has FI.

Actually you get a bit less power with high octane gas when it is not needed. Higher octane gas burns slower. Gas burns faster when closer to detonation.

FI? fuel injection? i hope you meant something else.
i agree with the rest, but prefer to run higher octane all the time as insurance. modern engines advance timing as necessary to make power, and they make assumptions about octane and take measurements of temperature (both ambient and coolant) to determine how much to advance.

Forced Induction/Intake: turbos & superchargers.

There is only so much timing advance you can have.
It is a balance one have to make depending on your driving style. Letting the engine ECU take care of some minor detonations is no big deal.

ditto! PREMIUM

i dont think its a coincidence.. i have firmly believed this for a long time now

i agree - if you decide to purchase an expensive car - it's common sense that upkeep would also cost a bit more - but then again---> common sense isn't too common!

ah, thank goodness