Hey there,
Here is some info I usually look at to compare cars - this is the evo4 (CN9A):
Evo4 LinkWebsite mentions 10.3L per 100km. This isnt exactly bad but its not good either. I drive the same shape GSR (1800cc) and get a better 8.1L per 100km.
However at reduced power (151kw as opposed to 206kw)
Evo4's are thirsty - probably more than the 1/2/3 series but it all depends on how hard you drive the car. Expect a tank town driving to last 250-350km.
Overall as long as it has been looked after (regular service) they are a pretty solid car.
Cheers
Stix