BMW announces sub-100g CO2 diesel

UPDATED: 18/09/2014BMW has announced one of the world's most efficient four-cylinder diesel engines, at the same time confirming it will be rolled out across most of the range.

The German car-maker has already announced the inclusion of the new 2.0-litre 140kW 400Nm engine – codenamed B47 - in the 2 Series coupe, Active Tourer and 5 Series, but BMW Australia says customers can expect the new diesel in more models.

Logic says these will include the mass-selling 3 Series and 5 Series sedans and X3 and X5 SUV ranges, which currently have a less advanced 2.0-litre four-cylinder diesel.

BMW says that under the bonnet of the 2 Series coupe, its new engine consumes as little as 3.8-litres of diesel per 100km when paired with a newly developed eight-speed transmission, and produces as little as 99 grams of CO2 per kilometre.

Those figures put BMWs latest compression ignition unit in direct competition with super-efficient engine producers such as Jaguar, which claims its 2.0-litre Ingenium diesel also consumes less than 4.0L/100km and pumps out less than 100g/100km – although the Indian-owned British company has not yet revealed power figures.

Powering the larger and heavier 520d with eight-speed automatic transmission, the same engine's fuel consumption increases slightly to either 4.1 or 4.5L/100km depending on tyre selection, while CO2 emissions sneak over the 100g mark to either 109g/km or 119g/km.

The significant fuel and emissions savings are a result of lighter construction, which has shaved 2kg from the alloy engine, plus more accurate solenoid injectors, a new variable-rate oil-pump and a redesigned intake geometry.

Noise emissions have also been cut, while idle-stop system operation has been improved.

The arrival of the new high-performance engine coincides with the announcement of new manual and automatic transmissions, firstly on the 2 Series coupe range.

A six-speed manual gearbox and eight-speed automatic transmission have been developed specifically to optimise the new frugal diesel, enabling the high fuel-efficiency while still allowing the 220d to get to 100km/h in 7.0 seconds (7.1s manual).

Diesel 5 Series performance has also improved with the introduction of the new engine, and the 520d 0-100km/h dash has dropped from 8.1 seconds to 7.9 seconds, when fitted with a manual gearbox or 7.7 seconds for automatic transmission variants.

In its top-performing state of tune, BMW's current 2.0-litre diesel produces 160kW and 450Nm of torque under the bonnet of the X5 sDrive 25d, but consumes 5.8L/100km.

At the other end of the spectrum, the 2.0-litre diesel 118d hatch produces 105kW/320Nm, while returning fuel economy of 4.4L/100km and emits 132g/100km.

The first high-efficiency engines will touch down in Australia in the 2 Series Active Tourer in November, with the first economy-boosted coupes expected at about the same time.

After that, the new engine is expected to trickle into other BMW models from next year.