Compounding the massive carbon footprint left by all these old-skool engines is the rotten traffic. City streets can be as wide as twelve lanes — though lanes are mere suggestions for the citizens of Buenos Aires. Cars cram the smaller side streets, with drivers idling at red lights and honking in frustration. Even ambulances have a hard time getting through.

I saw not one hybrid or electric car on the streets in the week I spent in the city, but I did see a sign of green hope, like the single plant Eve retrieves from a ruined Earth in Wall-E (why yes, it was the in-flight movie. Why do you ask?). Argentine petroleum company YPF has billboards along the city’s streets informing the diesel-choked drivers that clean diesel is on its way.

The web site (which is in Spanish) lists the advantages of what the company is calling D-Euro diesel: cleaner combustion, more miles per gallon, and fewer emissions. The fuel will have fewer than 50 ppm of sulfur, closer to the 15 ppm in the ultra-low-sulfur diesel used in the U.S. D-Euro diesel is classified as Bin 4 in Europe.

Photo of Bs. As. buses by blmurch.