Ya according to the owners manual it should return 29 mpg .... but to get this you won't be having any fun, which kinda defeats the point of buying an RS200...
I agree with Noel, you wont be getting 29mpg. Picked mine up on Friday, filled the tank, have done about 200km and have just over half a tank left, but then again I only got it Friday and am having way too much fun to start driving sensibly just yet :D