It may seem like you’re saving money when you climb in your car to pick something up at the store, or use free site-to-store shipping. But when you take into account the total cost of owning and driving a car, sometimes ordering the item at home without leaving the couch is more economical, even if you do have to pay shipping. How does that work?

Every year since 1950, the American Automobile Association has put out a brochure calculating how much it costs to own and operate a car. It includes registration fees, maintenance, gas, depreciation, even finance charges. (On average: that doesn’t apply to you if you bought your car in cash, naturally.)

Here’s an example: say I want to go to my favorite yarn store eight miles away to buy something. I have a medium-sized sedan that I don’t drive much, so according to AAA it costs me 73.9 cents per mile to get there, or $12.12. Shipping for the amount of yarn that I typically buy runs around $5, theoretically saving me money. On the other hand, the cost of just the gas for that trip is about $2.60. The federal mileage reimbursement rate puts that same trip at $8.26 at 51 cents per mile, more than the shipping charge.

Do you think AAA’s math holds up?

Is it cheaper to pay shipping for purchases than to drive to the store? The answer may surprise you [MLive] (Thanks, Simon!)
Your Driving Costs 2011 [AAA]

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