Going on a road trip to vegas with 2 friends in MY CAR. How should we split gas?

As i said, im taking my car to vegas. I was thinking that they should pay for the gas since im driving my car (far). But i decided to pay a little just to be fair. Last time i went, it costed around $200. So i was thinking i pay $40 and them paying $70 each. Is that fair? I dont think i should pay the equal amount since im taking my car and ill probably be the one driving most of the time. Let me know wat u guys think.