Can renting a car save you money?

Dedicated readers of this blog will recall that about eight months ago, I calculated the cost-per-mile of driving my car. In the end, I concluded that it cost me 40.2 cents per mile to drive my car at that time (the cost will always vary because of the changing price of gas).

Today I'm wondering if -- given the costs of driving your car -- it can be cheaper to drive a rental car in certain situations.

First, let's break down the cost of driving per mile, as I calculated them: 16 cents for gas, 8.6 for maintenance, 15.6 cents for depreciation. When you rent a car, you still have to pay for gas, but not for maintenance and depreciation. So, with a rental, I'm saving 24.2 cents per mile (8.6 + 15.6) in the latter two categories.

But that doesn't count the cost of the rental itself, and that's a key element in this equation. If I rent a car for one day and drive 100 miles, I've saved $24.20 in maintenance and depreciation costs. But almost all rental cars cost more than $24 for a day, so renting isn't saving you money. 

On the other hand, let's say if I drive 200 miles with a one-day rental that costs a plausible $40. Then I've saved $8.40 ($48.40 - $40) by not driving my own car.

Let's take a "real world" example. Say I want to drive from Long Beach, California, to Santa Cruz, California, spend one day there and then drive back. A total of three days. It's 369 miles each way, according to Google, for a round trip of 738 miles. 

Multiply .242 by 738 finds that I would save $179 in depreciation and maintenance costs for that trip. But how much would a rental car cost?

A little online searching finds a bunch of low-priced rental car offers from sketchy companies I've never heard of. But renting from a reputable outfit like Enterprise for three days would be a total of $125 (and some persistent price hunting might find a lower price).

So yes! You can save money by renting a car. But do your calculations carefully. You're going to save most for a long-distance trip over a short period of time. Be sure the rental car comes with unlimited miles. 

Also, keep in mind the "hassle factor": How will you pick up and drop off the rental car? If it's a long way to get there and back, that's defeating the purpose. Can you park your car at, or near, the rental place? Will you have to pay for the parking? Or maybe you need a ride there and back?  Each situation is different.