I just did a complete flush and refill on my rescue pony (02 GT) and after a couple of short drives I checked the coolant and the reserve tank was nearly empty. I remember thinking that it didn't seem like the system held nearly the 16 liters that the internet said was the capacity of the system (It took about 9 liters). I had to add over 2 liters to get the coolant back to the fill line. Is there really that much air in this system? Honestly the fact that this engine has no radiator cap makes this all a guessing game.