Single Day Car Rental vs Multi Day?

[MoYerclan]

We've always flown down a day early for our cruises, renting a car and turning it in near the port the next day. This next cruise is a short one in March and we won't be able to fly down in advance as usual but instead fly down that morning to Orlando and rent a car for the quick one way trip to Port Canaveral. It seems the price of the car rental that you turn in less than 6 hours later is $10 more than if you kept the car until the next day. What's up with that? Can anyone explain why that would be? Has anyone rented as if they're going to turn it in the next day but instead turn it in early and not pay more?

[6rugrats]

Even if you turn the car in early, you will be charged the same price. It does not seem worth it to worry about $10.

[cb at sea]

Since you won't have time to sightsee or anything with the car, have you checked prices for shuttles or other transport to port? It may be a cheaper option, and you wouldn't have to fool with picking up and dropping off the car!