An all-new core product of Mazda’s ‘Sustainable Zoom-Zoom’ strategy sees it global premiere at Paris this year; the Mazda6 MZR-CD 2.2-litre turbo diesel. This next-generation engine is another example of Mazda engineering expertise delivering high power and torque with lower fuel consumption and emissions. Developed exclusively for the Mazda6 line-up in Europe, the engine will be offered in three power derivatives to meet the needs of a wide range of diesel customers.
The second-generation Mazda6 was launched to high acclaim at the end of last year in Europe. Its emotional appeal, sporty styling, exclusive driving and quality experience and insightful packaging made it an immediate hit with European customers, selling 41,548 units (to end June 2008) and contributing to several all-time sales records in 2008. It is the second carline – after the ‘2008 World Car of the Year’ Mazda2 – to be completely renewed in a process that will replace the Mazda line-up with exciting next-generation products in the near future. Part of this programme is the new MZR-CD 2.2-litre common-rail, a Mazda turbo diesel that delivers some of the segment’s best power, fuel economy and operating refinement.
Mazda6 MZR-CD 2.2 DE – even more ‘Kizuna’
The all-new Mazda6 is designed to deliver what its developers call ‘Kizuna’, which is a strong emotional bond between the car and its owner. This bond is forged by the car’s sporty good looks, its high level of driving enjoyment and its quality. The driving part of this successful equation is now greatly enhanced with the launch of the new MZR-CD 2.2-litre turbo diesel. It is offered in three derivatives that produce between 125 and 185 PS of maximum output and powerful torque of 310 to 400 Nm.
All versions feature a variable-geometry turbocharger with vanes on the exhaust side of the turbine that are curved (rather that straight) and longer. On the intake side, a special seal is employed to reduce the clearance between the blade and the compressor housing. This architecture makes the turbocharger compact yet highly efficient at delivering robust torque and quick response to pedal input as low as 1,800 rpm.
The new engine also has a new common-rail injection system with four additional holes per injector (10 instead of the usual 6) that are smaller (reduced from 0.13 mm to just 0.119 mm) and help optimise combustion. By improving individual components like the fuel pump, engineers were able to increase the maximum fuel injection pressure to 200 MPa, one of the highest in the industry to date. This allowed them to further improve the precision of the engine’s injection timing and optimise the number of injections per cycle, the amount of fuel injected and the injection pressure. As a result, the engine achieves higher power and higher response with lower NVH, and excellent fuel economy with fewer emissions. Combined with a chain-driven double overhead cam (DOHC) configuration for smooth and efficient power delivery throughout the rev range, this translates into a marked improvement in acceleration in every gear.
To handle all this power, the new MZR-CD 2.2 turbo diesel has specially-designed aluminium alloy pistons that boast high thermal resistance. A half-Keystone cross-section top-ring with improved carbon scavenging abilities is used as well, and the groove for the top ring is made more durable with the adoption of a cooled ring carrier that increases the groove’s cooling capability.
Mazda6 MZR-CD 2.2 DE delivers ample torque and power
The all-new Mazda6 delivers an ownership experience that is one of the non-premium segment’s most exclusive. The new range-topping Mazda6 turbo diesel enhances this exclusive driving experience with a diesel powertrain that is one of the quietest and most refined in its segment.
To achieve this refinment, despite higher torque and power outputs, the new engine has a lower block with a very rigid aluminium-alloy structure, with the bottom of the cylinder block skirt and the cylinder block’s main bearing caps bolted to the lower block at 18 separate locations. This high structural rigidity suppresses booming noise and lowers radiated noise, and allowed engineers to optimise pedal response and engine sound for a refined acceleration feel. The cassette-type balance shaft contributes to the reduced noise, vibration and harshness (NVH).
Low Fuel Consumption and Emissions
This new premium diesel engine also meets the requirements of Mazda’s ‘Sustainable Zoom-Zoom’ plan by being frugal at the pump: all power derivatives use between 5.5 and 5.7 litres of fuel per 100 km (combined cycle), some of the segment’s lowest, by employing a newly developed EGR system with a cooler bypass structure, and by utilising the cooling effect from the engine’s lower compression ratio of 16:3. The common-rail injection system uses highly responsive solenoids that achieve a minimum injection interval of just 200 µs (the MZR-CD 2.0 is 300 µs) which speeds up the minimum injection interval by about 30 percent, improves its responsiveness and lowers emissions at the source. A plastic cylinder head cover also enables better oil separation of the blowby gases. In fact, the MZR-CD 2.2L DE is better than the MZR-CD 2.0 DE at this, even though higher power usually translates into more blowby gases.
Mazda’s weight-saving techniques were also applied during development of the MZR-CD 2.2 turbo diesel. The new engine’s oil cooler, for instance, is now made of aluminium rather than stainless steel and the cylinder-head cover is made of plastic.
A newly-developed diesel particulate filter system is introduced that is even better at lowering particulate matter (PM) emissions. This Mazda system employs technology never before used in a production car. It is able to reduce the number of times the PM filter needs to regenerate (in the NEDC mode) by half, and shortens the time necessary for a single regeneration by a third.
The new PM filter is made from a ceramic material with high thermal resistance and includes Mazda’s independently developed catalyst. The catalyst uses oxygen stored in the base material, in addition to the oxygen present in exhaust gases, to improve combustion of soot emissions. By increasing the volume of oxygen, this system makes regeneration of the filter faster and more efficient. The result is excellent emissions, without sacrificing performance or driving fun.
Mazda6 – the first Mazda with Rear Vehicle Monitoring System
This year’s Paris Motor Show also sees the introduction of a new rear vehicle monitoring system to the Mazda6 line-up. Employing wide-angle, 24 GHz radar, the system is a fully independent active safety feature. When driving at speeds over 60 km per hour, its radar modules located on the left and right side of the car inform the driver of an approaching vehicle that he might not be able to see at that moment, by illuminating an LED lamp in the A-pillar. If the driver operates the turn signal, the LED lamp flashes and a buzzer sounds to warn the driver not to change lanes. It has a range of approximately 50 metres in a wide arc on both sides, and the ability to function effectively even in adverse weather conditions.