Mercedes has obtained certification to sell more Bluetec diesel vehicles in the US.

According to Automobilwoche, the Blutec versions of the ML 320, R320 and GL320 will go on sale shortly. All vehicles with Bluetec technology have been certified as meeting bin 5 standards, and can be sold in all 50 US states.

Mercedes began limited marketing of the Bluetec E-class in California recently.

US emission standards are tougher on NOx and particulates than European standards, which means that exhaust aftertreatment is necessary.

Originally Mercedes had planned to market Bluetec in the US alongside Audi and Volkswagen, but the VW Group companies backed out of the marketing agreement last year and decided to use their own TDI badges.

Diesels are generally facing an uphill battle for consumer acceptance in the US. Most consumers believe that hybrids, fuel cells or flexible fuel vehicles are the way forward, according to research by car buyers' guide Kelly Blue Book earlier this year.