Don't use premium. You are throwing money away.

The VX is tuned for regular unleaded. I used 85 octane on my roadtrip with no problems whatsoever.

Regular unleaded prices ranged from $2.99 to $3.45 depending on the state and the location...ie, near a highway in California = expensive, but in small towns in Oregon = cheap. Pretty cheap in Utah, too...like around $3.10/gallon. Of course, I mean "cheap" relative to the CA prices. 3000 miles, average 18 MPG, average $3.25 gallon = I probably spent close to $550 on gas for that Moab trip!

Getting out of Seattle for two weeks? PRICELESS.