The fuel cost depends on the displacement of your car. Take 1.6 as an example, it is about 8 vehicles per 100 kilometers, and the fuel cost is about 230 yuan. So the unilateral toll is about 480 yuan, and the round trip is about 960 yuan.

If you take the train, take the hard sleeper middle berth 139 yuan, leave Chengdu in the evening and arrive in Xichang at seven or eight the next morning.

A car can take five people, and the cost of taking a train for five people is 695 yuan, which is more cost-effective than driving. It takes at least seven people to take the train to spend more than 1000 yuan, but if you drive two cars with more than seven people, the fare will double to 1920. In fact, it is cheaper to take the train, 7× 139=973, which is less than half of the car.

So it's always cheap to take the train.