In the last Timing is Everything post, we looked at an Enterprise rental where pricing fell off a cliff on the 26th day. This can happen in many cases when you your chosen pick-up and drop-off times fall on the border between daily or weekly pricing, or weekly and monthly pricing.

While that was an interesting and extreme example, not too many folks rent cars for a month. A week, now, that's a different story. To illustrate our point, let us take a look at a Thrifty rental in Fort Lauderdale, something we were recently researching for a customer. In the process, we found something quite surprising.

For starters, we'll be picking up and dropping off at the Fort Lauderdale airport (FLL). Let's begin the rental on July 12. We'll start with one day – returning on July 13. Then we'll add days to the rental to see how the price changes.

For the 1-day rental, July 12-13, we see that the price is $90.69 for a compact car with tax. Seems a bit on the expensive side for FLL, but a check of other rental companies yields similar rates.

OK, now let's extend the rental to 2 days from July 12-14. Now the rate jumps to $181.38. Makes sense so far since the price doubles when you add an extra day.

Now here's the fun part... Let's add a third day, meaning that now we're renting from July 12-15. Oh, look -- the price is now $153.13. We actually saved money ($28.25) by adding an extra day. Interesting.

If one extra day is good, then two extra days would be even better right? Sure enough, if we extend the rental to a fourth day from 7/12-7/16, the price actually drops further to $128.11. Now we've saved over $53 by keeping the car an extra 2 days. This is starting to get fun. Thank you sir, may I have another?

Alas, one more roll of the dice and we're totally crapping out. Adding a fifth day to the rental jumps the price from $128.11 to $340.07. Watch that last step; it's a doozy!

The price will now follow a fairly predictable march upwards as we increase the number of days. This trend will continue until you reach the 28th day where the price will drop from $1,411 to $925 (there's that monthly cliff again) from our last article.

While we focused on Thrifty here, if you click on the screenshots referenced by the links above, you'll see that most of the providers are clustered around the same prices. Conspiracy theorists will assume collusion among the companies, but the reality is more likely that they all monitor each other's pricing on a regular basis and adjust accordingly. You'll find this same herd mentality at work in the airline industry.

So what's the moral of the story? Don't always assume that renting for longer will cost you more. As we've shown here, extending your rental by a day or two can actually drop your rate rather than increase it. It's true that you'll pay a bit more in taxes the longer you keep the car, but in some cases, the underlying rate can drop so much that it overrides the higher taxes.

The next time you're pricing out a rental and you have some flexibility, extend it for a day or two and see what happens. You just might find yourself paying less and getting more. Here at AutoSlash, we're all about that.