Originally Posted by Kai

Of course they do, at least all 84-85 GSL-SE's and all 86+ RX-7s. Spec on them is 1-4.5+, but that's not important here.

As mentioned before, anything less then spec will make the car bog, any more and you're wasting gas. Due to the shear volume of places that say .45, I'd go with that, but .5 does make more sense to me.