Pardon my ignorance: why is the 7M-GE so much less efficient?

[finaltable]

I actually have a decent amount of money to spend. The reason I haven't gotten one before now is that we have two kids and I have been supporting the family on just my income so the idea of getting a less efficient/practical car has been something the wife wouldn't exactly support. She has gone back to work and I got a job that is going to require that I drive about an hour each way everyday. Since the alternative is that we move (and she REALLY does not want to move) I finally put my foot down and said "I took this job which pays more than I have ever made to support us and if I am going to be driving 2.5-3 hours a day I AM going to have a car I enjoy driving." She realized that I was right and supported me actively looking for a Supra. I probably could have bought a Mk IV but the Mk IV would have been less practical when it came to putting 2 carseats in the back. I expect to put several thousand into the car in the next few years making it "new" again. A complete repaint in in the works but that will be the last thing I do after getting all the mechanicals taken care of.