fuel depends on lots and lots of different things. For instance how you drive (hoon or grandma) and your location (traffic conditions/ congestion) and the overall condition of your engine.. (dirty o2 sensor, heavy breathing engine)
I could squeeze about 350-380 from full down to 1/4 but that was doing 80k's to and from work.. Jump on the m4 and driving around in traffic it dropped to about 300-350.. supras will be similar, maybe a little worse due to weight.