With my 91 RX7 NA in top gear I go 70mph@2800rpm and 80mph @3200rpm;
......with my RX8 in top gear I go 70mph@3500rpm and 80mph @4000rpm.
That's 25% more rpm on a more powerful engine. Shouldn't I be cruising at a lower rpm? And in SoCal 70/80mpg are my cruising speeds and I'm still being passed!

The top gear seems to be the same as on my 83 RX-7 - 3500 at 70. It would be nice if 6'th was a bit lower geared since the only thing I use it for is better mileage on the highway.

They probably did that so it feels torquey on the freeway, anyone know what the ratios on the 6-speed miata are? theyd probably swap right in.

First, Higher (taller) gearing makes fewer RPMs, i.e., 1st gear is "lower" (shorter) than (shift into high), 6th, etc. Likewise with rear end ratios.

Anyway, if you think the current '8s direct gearing is low at 4.44, I read last night that the R3 is being given a 4.77! No word on if the overdrive 6th gear will be made taller to offset. 0-60 times are way more pertinent for marketing than MPG in this niche, but you're not even out of 2nd to get there, so the higher 6th might be a possibility that I'd hope could be dropped into current trannys.