I've seen this discussion about two dozen times on this forum over the last four years (at least !). In my opinion, it comes down to why you bought the car. The Crossfire is designed to take advantage of higher octane fuel to give you better performance. Will it operate on 87 octane ? Absolutely.. the computer will retard the timing and make other adjustments and you drive all day on regular. Will you get optimum performance. Absolutley not.

If you plan on driving your Crossfire like a Buick, then go ahead and run regular gas and save yourself a whole $8 a month or so. But if that's the case, why the hell did you buy the car to begin with ?