Because each car can only carry 24 barrels of gasoline at most, every barrel of oil consumed by one car should be supplied to another car to ensure its sufficient oil. That is to say, a car consumes two barrels of gasoline when it leaves 60 kilometers, and one barrel when it returns, and another car consumes one barrel every 60 kilometers (the drawing is clearer).

Let's assume that the car that goes near returns at a distance of 60km from the starting point, and the car that goes far returns at a distance of 60y km.

It will consume 2x barrels of gasoline when leaving, and X barrels when returning.

2x+x=24 x=8

So a car should return at a distance of 8*60=480 kilometers from the starting point.

The other car (y-8)*2+8=24 gets y= 16.

That is, the car farthest from the starting point has traveled 16*60*2= 1920 km.