The BMW 335d clean diesel sedan

The price would most likely be 10 to 15 percent higher than the non-diesel—pushing the sticker beyond $80,000.
There are other reasons for BMW to consider carrying the European 730d to American shores. A diesel with fuel economy in the mid-40s would help BMW meet more stringent fuel efficiency standards on the way. As a comparison, a conventional version of the new 7-series is expected to grant just 16 in the city and 24 on the highway.
BMW dealers from the US recently gave the new 7-series diesel a test drive in Munich. “They all told me they wanted it,” said Jim O’Donnell, president of BMW North America. “It wasn’t in our plans, but we’ll look at it.”
If the 730d makes it to the US, it will probably utilize a clean diesel system similar to the one found in the BMW 335d. The technology, known as BluePerformance, utilizes a fluid called AdBlue, which is injected into the exhaust system to reduce oxides of nitrogen. BluePerformance is very similar to the Bluetec system found in Mercedes Benz diesel vehicles.
My estimates were based on the mileage for existing diesels. The 335 diesel, a less massive car than the 5- or 7-series, is listed elsewhere on this website with a 29 mpg combined figure. The E series Benz diesel (which is still trimmer than the 7-series BMW, and closer to the weight of a 5 series Bimmer) gets 23 city/ 32 highway/26 combined, from the EPA. Even the Jetta diesel gets 30mpg EPA in the city, and I doubt the 5- or 7-series will do better than that.