I actually averaged 24.5 mpg this last tank which included a spirited 140 mile drive with the Z crew last weekend. Not bad! Of course the trade-off is when you apply pressure to the throttle nothing actually happens.
Anyways, I applaud BladeZ for doing what he needs to do for a house. That's more important than a car. So my advice is just STAY THE COURSE and resist temptation! Get a fun car after you have a garage of your own to put it in, otherwise you sold the Z for no reason.