'04 Sentra SPEC-V gas???? premium?

just wondering what kind of gas you guys put in ur spec-v's. it says on the gas tank that premium or super is "recommended," but i don't know if it's worth the extra buck to pay for the gas. let me know what u all think

Check you manual, and follow that, to be sure. On one hand, you want to make sure you are running on the correct octane, and the other, no need to spend more money if you don't have to. There is some debate about this, however.

89 octane is fine. i used 87 or 89 in my spec while i was up north. at least 4 months without any problems. now im in LA and I use 91 because of the hot climate.

you don't want to risk detonation (igniting the air-fuel mixture w/o the spark plug).
i didnt think to look at your location, but if you live in a hot climate at low elevation, you should go with 91.
if you have relocated your knock sensor like lots of spec owners, you should go with 91.
if you drive fast for extended periods of time (causing high engine temp), you should go with 91.
pretty much, if you can afford 91, go with that.
there are no disadvantages in using it.

"you don't want to risk detonation (igniting the air-fuel mixture w/o the spark plug)."

that's what the knock sensor is for, if there is any detonation it will retard timing to prevent it. You're right though, if the knock sensor is relocated then 91 or 93 should be used as a precaution.

i live in the bay area (cali)...thanks for the input everyone. is it bad to keep switching between different octane gases?