put in 91+

there is a knock sensor that will retard the timing to allow for lower grade fuel, but the performance will drop way down

say you fill up the tank once a week, you'll end up saving what, $150-200 a year? granted that alot but for the extra 3 bucks in the tank i feel a whole lot better just putting the premium in.

and stop whining about gas prices. i see people paying upwards of a dollar for a bottle of water which is less than a 1/4 gallon and not saying "oh my god water is prices are so high i think i'll switch to drain water" :rant: sorry i'm just sick of hearing it, pay the money, you need your car, they have you by the balls, live with it

:edit:

and to directly answer you in simple terms

you can use lower than 91, but it is highly recommended you stick to 91+

also if you do use anything lower than 91 at least use 89, i'm nto sure it will be able to retad the timing that much to compensate for 87