I got an 03 GLi as well, and I get as least 450km on a full tank (~40L) - even with the more than occassional thrashing. The only thing I've done to it is put a SRI in, and I don't think that would make a significant increase in petrol consumption. I usually fill up with BP Ultimate or Shell Optimax? (forget the name). Is your car an auto? Mine is, and I think if they were manual we would be able to get 500+ like the other manual drivers with our model. So yours is pretty much standard. I thought I was the only one getting crappy fuel economy.