Two speed rear?
 

Looking at the gear ratio on the new rx-8 (4.77) I have to stop and wonder if anyone is making a two speed rear for it? Mainly so you could get better mileage when on the highways and you're not as worried about performance. And it would probably be easier to install than to mess around with MT gear ratio's.

(anyone else wonder why they didn't make the 6th gear a lot taller for better hwy mileage?)

^maybebecause below 3k rpm(60mph in 6th in the 04-08 rx8's) almost bogs the motor down and starts to seem to use more fuel(at least in my findings)

Strange as it might seem it may actually improve the fuel mileage to rev a bit higher.

If I set my cruse control to 60 MPH on a 90 mile drive down a flat freeway I get 21.3 MPG. At 70 MPH I get 21.7 MPG despite the increased drag. I've tried that about a dozen times on my daily commute.

Normally I drive 75-80 with bursts to 90 and pretty much average a tad over 20. Except when I have some city driving...

Best MPG I've seen was a bit over 23, worst I've had is about 16. I don't flog the car more then a few times every tankfull.

Keep in mind I run a 20% ethanol mix.

^exactly

Would you be willing to spend $3000 to have it?

Next ....

Maybe. Got something in mind?

^3k for a diff? I'll pass thanks!