INFINITI GOES DIESEL … QUIETLY

Bespoke new 3.0-litre V6 direct injection diesel
Class leading torque output of 550Nm
Exceptional refinement…
… with outstanding performance…
… competitive CO2 emissions and economy…
… add up to a true Infiniti performance diesel
Alliance designed engine for new EX30d, FX30d and M30d models
Sales due to start in the summer, prices to be confirmed
Diesel opens new opportunities for Infiniti
ROLLE, Switzerland (February 19, 2010) – Phase two of Infiniti’s quiet assault on the European luxury car market is underway with the arrival of a newly developed 3.0-litre V6 diesel. The engine, the first in the brand’s 20 year history, has been specifically designed to deliver high levels of refined performance in line with Infiniti philosophy. It will initially be available in both the acclaimed EX and FX crossovers and later in the Infiniti M luxury performance sedan.

The new diesel is a key element to Infiniti’s continued growth in Europe. Launched barely a year ago, the Infiniti range has won high praise from customers and the motoring press alike. Now with five established model lines – G37 saloon, coupé and convertible, plus the EX and FX ranges – more than 2000 Infinitis have been sold across 15 markets despite the marque’s launch coinciding with the worst global recession for decades.

A sixth model, the Infiniti M Line, will be launched during 2010 and it, too, will be available with the choice of petrol and the new 3.0d unit.

“The sales success enjoyed by Infiniti in Europe against a backdrop of financial uncertainty proves the cars’ appeal to a discerning audience. We have established Infiniti as the luxury performance brand thanks in part to the remarkable multi-award winning VQ petrol engine that powers most of the models in the range,” said Jim Wright, Vice President, Infiniti Europe.

“We were aware from the outset, however, that for Infiniti to offer a complete range a powerful diesel engine was a must, especially in the European premium SUV market where diesel represents the bulk of sector sales.

“Although we did investigate the possibility of adapting an existing large capacity diesel for Infiniti, we quickly established that nothing on the market met our exacting requirements. We needed an engine that delivered not just stunning performance but exemplary refinement too. For that reason, with the Alliance we decided to develop our own engine, a performance diesel worthy of the Infiniti badge,” said Wright.

The performance figures speak for themselves. Developing 175 kW (238 PS) and a remarkable 550 Nm of torque, with standard seven-speed automatic transmission the new engine sends the EX30d to 100 km/h from rest in 7.9 secs and the FX30d in 8.3 secs. However with all that torque, it is in their overtaking performance that the Infiniti’s advantage will be most felt. (All figures subject to final homologation.)

The V6 diesel in detail
Designated V9X, Infiniti’s new V6 diesel has been developed in Europe by Infiniti engineers working with other engineers from Renault and Nissan. It is made at a state-of-the-art facility in Cleon in France, some 100 kms west of Paris. From the very start of development, the new unit was created to answer Infiniti’s demands for a powerful but exceptionally refined diesel engine, quiet enough in use to match the high standards set by the petrol engine.

The unit will also be used in cars from Renault and Nissan, allowing both those brands to broaden the appeal of specific model ranges at the same time as boosting production volumes of the engine. Unusually, V9X will power front-wheel drive, rear-wheel drive and four-wheel drive models.

With Infiniti’s specific requirement for a compact unit delivering high levels of power and torque with competitive emissions, strong economy and unrivalled refinement leading the development, work on the direct injection 2993cc V6 began in 2005.

Although a V8 diesel engine was investigated, the V6 format was identified early on as the ideal layout for the unit, providing the optimum balance between overall performance, refinement and volume potential across the three Alliance brands. Target performance was 238 PS (175 kW), 500 Nm of torque and early compliance with forthcoming Euro 5 emission legislation.

At the same time, the engine bay architecture of the EX and FX models – designed initially as petrol models only – called for a compact engine which, if it were to be used in both transverse and longitudinal positions, would need to have a comparatively narrow vee angle as close to 60 degrees as possible.

Engineers decided that the ideal vee angle for the unit would be an unusual 65 degrees. This offered an excellent compromise between crankshaft balancing, crankshaft and cylinder block reliability and engine packaging with the 65 degree angle wide enough to allow the single turbocharger to be neatly mounted within the vee.

But perhaps the key element to the success of the new V6 is the material chosen for the engine block. While some rivals tend towards aluminium-alloy cylinder blocks to reduce the weight of their diesel engines, development engineers felt that to achieve the desired levels of refinement an aluminium block would need extra material added to increase its stiffness and reduce noise levels. It might also need extra complexity added in the form of balancer shafts to boost refinement, but all these additions negate the weight advantages of an alloy block.

Conventional cast iron, however, would place too much weight over the front wheels and lower the levels of driving pleasure offered by all Infiniti vehicles. In its place, the engineers chose Compacted Graphite Iron (CGI), a material that offers all the benefits of cast iron and more – it has higher levels of stiffness and noise absorption – but without the weight penalty. And while CGI is heavier than a pure aluminium block there is no need to add stiffening ribs or extra sound deadening material so the weight gain is comparatively modest.

CGI was patented in 1949 and its first commercial application was for the brakes of Europe’s high-speed trains. It is 75 per cent stronger and up to 75 per cent stiffer than grey iron, the most common form of cast iron found in engine cylinder blocks. It also performs better than aluminium at higher temperatures when it is up to five times more fatigue resistant. Best of all, the weight of a typical engine block can be more than 20 per cent lower than an equivalent cast iron block.

To manage the high loads on the engine structure commensurate with the impressive power and torque outputs, the overall stiffness of the engine structure was optimised at the design stage by incorporating a number of specific features. These included a large and stiff coupling face between the converter housing and the engine; the CGI cylinder block with semi-deep skirts; direct bolting of ancillaries on the crankcase; an integrated engine bracket in the upper timing covers; a structural oil pan; a stiff torque converter housing and an axial driveline bearing on the gearbox side.

At the same time, to reduce vibrations inherent in a diesel engine and avoid unwanted resonances in the rev range, intensive structural optimisation during the preliminary design stage used finite element calculation to identify both the source of vibrations and to establish the ideal structural form of the block.

The result is a compact, architecturally stiff and refined unit that by itself delivers two of Infiniti’s design goals: high levels of refinement and no loss of chassis balance. In tests, Alliance engineers have determined that the V9X engine has the lowest 250 Hz and 500 Hz vibrations of all the benchmarked engines.