We can take into account that no exhaust pipes or mufflers were found at Roswell. In fact, the propulsion system of the downed disk was a complete mystery.
Through other sources we can see that beamships (ufo's) operate with a variety of systems, most of which use energy abundant throughout the universe. Most agree that source is the tachyon.
Compare this to our funky cars with their need for gasoline. Internal combustion engines have been in use for well over 100 years. They're nasty, inefficient, and require...uh...fuel
But wait: WE require fuel, too, don't we? Yes, now that I think of it, we do. Yet the ascension indicates that we will change our mode of sustenance to LIGHT at some point of our transformation.
One might do well to consider the caterpillar, who bulks up before entering the cocoon, emerging a butterfly with a completely different structure, and gentler nutrition requirement.
After all: we ARE getting wings for flight
This is not to be in conflict with Alexplatups' post at all: we do still need to eat, and eating sensibly is important. But it answers a question many have about the future.
I will admit: I'll miss lasagne.
from: the Shift: Wherefore Shall We Eat?