I'm all for alternative fuel, and think that would be the ultimate mod for our VX. Mine just hit 80,000 miles today, and while I'm sure this motor has a lot of life left in it, I'm already starting to think about what I'll do when its days are numbered. A good engine swap that increases performance AND fuel economy (while also being good for the environment) would definitely ensure that I hang onto my beloved VX until it becomes a classic.