im wantin to buy an RX-8..but first what kinda MPG do the manuals get and how long till major problems start occuring usually

anywhere between 10-22mpg
anywhere between immediately to who knows

What kind of driving will you be doing? To get 22 MPG you need to spend most of your time in 6th and under 4,000 RPM. If not your going to get around 16 MPG.
I am almost at 120,000 without major problems. I did get a rebuilt engine around 110,000 but I could have put more on the old one.

I have seen 8 mpg before and 23 at most so it all depends on the kind of driving u do and how hard u run it...Problems it all depends on the above factors

I have a manual and usually get around 17-18 mpg, (65% highway/35% city). I've had the car over two years, no major problems. I wish everything I owned was this reliable.

buy another car

I am getting 15.9 driving probably...

80% city/ 20%highway..

Probably 230-240 to a full tank but thats pretty much driving it pastt he light fillin up about 13-14 gallons

fill ups cost me 52-55 bucks SUPREME ONLY!

I usually fill it up one i hit a quarter left and thats about 11 gallons and it costs 45-47 bucks

about 189 miles or so

IDK about problems as ever car is taken cared of differently

I get 16-17, Im at 66K with a lot of transmission problems between 20-45K resulting in a new trans, a couple of fixed oil leaks all under warranty and now Im still with my original engine running smooth.

~16mpg. Driving style doesn't have a huge effect either, which is both a good and bad thing.