We talk quite a lot about how global regulations aimed at improving fuel efficiency and reducing carbon emissions will lead to much smaller, more powerful engines.

Latest case in point? Would you believe a four-cylinder Mercedes-Benz S-Class?

Just to be clear, this is the big Benz. The one beloved of burgermeisters for half a century, the symbol that you've arrived, that you can afford--and deserve--the biggest Mercedes-Benz sedan they make.

Four cylinders? Really?


The 2011 Mercedes-Benz S 250 CDI uses a 204-horsepower 2.2-liter turbocharged four-cylinder diesel engine. It's the first four-cylinder S-Class in more than 50 years.

While 200 hp may not seem like much for such a big car, the more relevant specification is torque: a remarkable 369 foot-pounds at a low 1600 rpm, which Mercedes-Benz says is the equivalent of a six-cylinder diesel.

The car does 0 to 62 mph in 8.2 seconds, neither swift nor embarrassing for an S-Class. Top speed is 150 mph.

The engine includes start-stop technology as standard, adding to its fuel efficiency, which is quoted at 41 miles per gallon of diesel fuel on the European test cycle.

The S 250 CDI goes on sale early next year, but only in Europe. We won't see it here in the States, where the cheapest and most fuel efficient S-Class continues to be the 2011 Mercedes-Benz S 400 Hybrid.

We're not sure, but we think that makes the Mercedes-Benz S-Class the only car in the world offered with a choice of four-, six-, eight- and twelve-cylinder engines, as well as gasoline, diesel, and hybrid powertrains.