I've had my VX since '01 and I've been consistently getting about 330 miles per tank using 87 octane gas. It normally takes a little over 300 miles before the gas light comes on steadily. 63K miles and still running strong.
My city/highway driving ratio have varied over these years. I'm convinced that being in Florida (A/C on most of year, no hills whatsoever around here), some minor upgrades (K&N stock filter, synthetic oil all around) and an average driving style have contributed to the acceptable (by VX standards) gas mileage I'm enjoying.