"Make Mine Unleaded"

I recognize that a common joke at a coffee shop is to ask for "unleaded" instead of "decaf", but apparently George Will takes that quite literally....

Because the average price of a gallon of gasoline has swiftly plunged from the post-Katrina high of $3.07 to $2.15 (compared with $185.60 for a gallon of Starbucks espresso), the recurring populist fever that always follows oil price spikes has broken. It will be back.

So is he suggesting that we economize by drinking gasoline instead of Starbucks espresso, or is he pioneering a line of cars that run on coffee? [Insert smiley here for the sarcasm-impaired.]