It's interesting that planes can use leaded gas...doesn't that lead do the same harm as if it were used in a car?

As for you're Eclipse, check the manual, use whatever it recommends for the minimum.

I know my MX-6 has a knock sensor, so if I were to put in lower octane gas, even though it's supposed to use 91+, 89 or 87 won't kill the engine because it will automatically adjust due to the knock that might occur. Of course it will reduce performance some as well. I don't sweat the extra $0.20 for the premium when I have to use it.

Isn't it interesting that the difference between the 3 grades is almost always $0.10 away from each other, regardless of how bad the oil crisis is for us? And BTW I just saw a Shell with gas for $1.80, $1.90, $1.99. I guess they didn't want to cause sticker shock for those getting premium seeing $2.00. Or they don't have their 2's out of storage (;