July 11 is National 7-Eleven Day. For the past few years, the chain has been rewarding customers by giving them a free small Slurpee to celebrate. Free sounds good, doesn’t it? But even free comes at a cost. What if you live 20 miles from the nearest 7-Eleven. Is it worth jumping in the car and grabbing your free beverage?

To find out, we imposed upon our good friend John Rafferty at Devonshire Associates for a national inventory of 7-Eleven locations. We were surprised at the map, or at least our ignorance. Having lived in three metropolitan areas over the years — Los Angeles, Dallas-Fort Worth, and Washington DC — we naively assumed that 7-Eleven was everywhere. Turns out, much of the nation is deprived and we didn’t know it.

Also, we have learned that there are other brands which are owned by 7-Eleven, Speedway and Stripes, but for now, we will stick to 7-Eleven.

With a free Slurpee, you might be tempted to hop in your car and go get yourself one. If you live in Billings, Montana, we suggest that you rethink your plans, since the cost of gas will far exceed the value of the Slurpee. So, how far should you be willing to drive to make the free offer economically viable? The national price of gas is about $3.50 a gallon for the regular stuff, and your average vehicle gets about 25 miles to the gallon. If you do the math, the 7-Eleven has to be within about 4.5 miles, since we assume you will eventually be coming home with your free bounty. For the lucky ones, the nearest 7-Eleven is just three blocks away, so this clearly is a good deal. For others, where the nearest location is 17 miles away, we have a solution for you.

Get some friends who are willing to share the cost of gas. How many friends? Depends on how far you have to go, so we created this handy map that shows you how many friends you will need to pile into your trusty old Honda.

We limited it to 12 friends, beyond which you clearly need a truck. 12?  Well, some years ago we did some scientific research and determined that the maximum number of college girls (including your now wife of several decades) you could cram into a 1978 AMC Gremlin for a Baskin-Robbins run is 12, excluding the driver. Our attorney insists that we state, for the record, that we do not recommend that you try this at home lest you annoy the local constabulary. The rules at the time were that only the driver was required to wear a seatbelt and that you could not obstruct the rear view mirror.  We do not regret the experiment itself, only shameful fact that we owned such a car in the first place, which was as bad mechanically as it was hard on the eyes:

On to the map –

Does this really qualify as a “National” day? We think not, but for those of you who live in the red areas, you can take advantage of the offer even if you have no friends. Cheers to 7-Eleven, a day we think merits inclusion in the short list of national days.