I usually remove about 40 pounds worth of miscellaneious pieces from the hatch including my spare tire and jack. I also try to arrive at the event with as little gas as possible. I've never suffered from fuel starvation.

Having said that, I don't think removing this kind of weight makes any difference to me, especially since I've made some of my best runs with a person in the passenger seat. However, it doesn't hurt either, and only takes three minutes of my time.