Yes this is a gay argument but you may be right about the motor being the same. The tuning is different however. The EX had lower MPG on the sticker because it's tuned up more than the others. The HF could be special ordered with a really de-tuned motor. The difference between models is not just interior (and wheels). The EX was the only model that had 4-wheel ABS. I don't remember if hers is a 2003 or 2004, maybe there's a difference between the years.