I have a 70L tank and after changing to a K&N air filter and cleaning my iridium spark plugs I get approx 550 km, until the light comes on and the needle is flat on 'E'. I have read that I have another 10L after the light comes on.
That works out to about 26 MPG.....
I was hoping for more, but .............and also the gasoline I get is 95 RON at best, not very good for the IS 200. Hope that helps, one thing is the car drives like a dream.
trinilex........