In North America diesel enthusiasts continue to live under the cloud of VW’s diesel emissions scandal. In Europe major cities are threatening to ban internal combustion engines all together, diesels first. But while that’s happening, manufacturers are introducing new versions of common rail diesels that are more powerful, more efficient, and yes, cleaner than ever. Where some see diesel’s swan song, others are looking at the dawn of a new era of clean diesels, and BMW and Mercedes are leading the charge.
We recently shared info on Mercedes OM654 diesel which replaces the OM651. And BMW is replacing the N series diesels with a new B series, in 3, 4 and 6-cylinder versions. The results are impressive: more powerful, more efficient, cleaner. All have 4 valves per cylinder, variable camshaft timing (VANOS), balance shafts, and electric, on-demand water pumps. All the engines will be assembled in BMW’s Steyr plant, in Austria.
Like Mercedes OM654, the B47 4-cylinder diesel is the workhorse of the line, with power output ranging from 114 to 227 HP, depending on turbo, fuel system, tune, and application. Bosch and Mahle have worked together to make single scroll turbos with variable geometry for some applications, while higher output versions of the series will use multi-stage turbos as we saw in the N and M series engines, particularly the M57 in the spectacular 335d.
Efficiency and Noise Reduction
The new engines show up to 13% improvements in fuel economy compared to the N series engines, while making more power. And it does this while increasing efficiency by over 10%. And they’re quieter: BMW uses acoustic panels on both gasoline and diesel engines to reduce noise. Interesting note: those panels also help the engine retain heat while sitting overnight, thus requiring less warm-up time when started cold. All engines have higher emissions when cold, so this technology reduces the impact of cold starting emissions. And yes, these engines are Euro Tier 6 compliant.
Plans for North America
The most likely candidate for replacing the N47 in the 3-Series and X3 cars in North America is the 190 HP version, which makes 295 lb/ft of torque. We’re not sure if it will appear in the 2018 version of the F15 3-Series (shown) or be launched when the new 3-Series debuts in the Summer of 2018 as the G20 2019 model. Either way, it’ll be matched with ZF’s excellent 8-speed torque-converter automatic.
Although the 3 cylinder 1.5L version will be available in Minis outside the US, it’s unlikely we’ll see it here. However, hopes are better for the 6 cylinder B57 engine in the 5-Series sedan and X-5 SAV in North America. The 6 cylinder engine makes 260 HP and 441 lb/ft. of torque.
Clean Diesel Lives
European automakers state that diesels are their best hope for meeting upcoming CO2 regulations. The much talked about upcoming bans on diesel cars in European cities and countries, if passed, (and that’s a big if) focus on new vehicles at the time the bans are implemented. This means that most of us will see ICEs on the road, including diesels, for the rest of our lifetimes. The new generation of BMW and Mercedes diesels are harbingers of how diesels can retain the benefits drivers love and also be green.