Blue Diesel

Over here in Europe, we’re used to BMW sitting at the top of the diesel tree, but over in North America, they’ve never seen a diesel-powered BMW outside the Spartanburg factory gates. It’s all down to do with our different views on what constitutes harmful emissions, but this month’s Detroit Motor Show sees BMW bring diesel power to the US and Canada for the first time.

Of course BMW diesel engines are already among the cleanest you’ll find but US emissions standards require different technology from the European regulations, which is why the twin-turbo diesel gets an oxidation catalyst, diesel particulate filter and an SCR (selective catalytic reduction) system in order to reduce the nitric oxides.

In the world of low-emissions cars, blue seems to be fast becoming the new green, which explains why the US diesels are branded ‘BMW AdvancedDiesel featuring BluePerformance’. The name comes from the solution of urea known as ‘AdBlue’ which is injected into the catalytic converter in order to convert the nitric oxides in the exhaust gas into environmentally friendly nitrogen and water vapour. It’s a technology which is already in widespread use in higherpowered heavy trucks here in Europe and the AdBlue solution is injected only in very small quantities, which is why the storage tank could be designed so that it only needs replenishing at every engine oil change.

Initially only the 335d and the X53.0sd will be offered and will both be so-called ‘50-state’ models which means they’ll be available nationwide.