I took delivery of my 8 on Halloween. I only have 700+ miles on it, so I have, on my ticket, only put in two tanks. Only about 14.5 mpg each :-/

I am planning on going from here (NC) to TX after Christmas (4000 miles). I have searched, but there is no mention of suggested crusing speeds that I can find. My question is does it make a difference if your highway speed is above the second port operating at 3750 rpm in regards to mileage?

I have read on Canzoomer's ECU mod. I could not find any octane requirements. Maybe I was not too thorough, but does it require anything above 87? I bought this car because competing cars I was looking at (IS300, 330i) took 93 octane. I plan on forever using 87.

Are there any form of wheels skirts to deflect debris? I have a huge distaste for body cladding, but the constant barrage of gravel and grit running down the side of the car bothers me. Id be willing to screw think black plaster behind the wheel if I had to.

What in the world is that whistle behind the drivers ear? I do not have a sunroof, and all windows are closed, etc, but that whistle is rather annoying.

I read on the noisy clutch and clunk at startup, and Im cool with that if they are documented as non-problems. I like this car, its definitely a step up from the Explorer I still drive, and sticky fast to boot. Good play on the car, Mazda. Lets see what the mileage fairy brings.

Thanks all, I look forward to lurking here for a while.

i think if i can recall, the rx8 user manuel says you need 91octane or higher anything lower could cause damage to the engine...?

No...the manual implies that 87 may be used, if you do not plan to push the engine to it's maximum potential...IE: You are going to cruise across a couple of states and don't know you are not going to really punch it anywhere. So if you cruise at 3750, you should be fine. Lots of people say that they have been using 87 for a while and no biggie.

I get a vibration and slight whistle too....even when the sunroof is closed! Why would we get that vibration just have the driver window down a bit and all the rest closed!? Guess i will have to crack the passenger window all the time. Manual says you can use 87 Octane but recommends 91. I use 89 myself.

On the highway I cruise at between 80 and 100mph, which puts rpms over 4000. No joke, around town i get around 12-13.. on the highway it damn near doubles.
I always run premium, be it 93 or 94. Who knows when you are gonna have to nail it hard. I like the extra insurance, and would throw in a few gals. of 100 octane each fill up were the station close enough ;)

93, 94, 100 ?? My god, Psylence, you make me feel that California is so obsolete. We have 91 as the highest here. But for Waldo, I would recommend 91 as Mazda said. Just because your new RX8 can take 87 now, doesn't mean it won't get damaged slowly bit by bit. It's like a cancer, when you see the damage years later, it might be too late but to spend $5000 for engine rebuild.