Diesel engine technologies have recorded tremendous growth in recent years, driven by the increasing market share enjoyed by diesel engines in Europe.

Modern diesel engines are being compelled to comply with various emission regulations and performance requirements that are helping drive the evolution of the technologies from the conventional to the more radical and innovative.

Researcher Frost & Sullivan estimates the total European next-generation diesel engine technologies market to be worth $US6.34 billion in 2004. The market is forecast to increase at a compound annual growth rate of 3.6% to reach around $8.26 billion in 2012.

Diesel engines are gaining in popularity in Europe, penetrating even vehicle segments that have traditionally been considered gasoline engine strongholds.

With the introduction of sophisticated technologies such as variable geometry turbocharging and common rail direct injection, the penetration of diesel engines is expected to increase from the current 45% to about 53% by 2012.

Among the various technologies, boosting techniques, engine management systems and exhaust gas after-treatment systems are attracting the maximum interest from vehicle manufacturers. Valvetrain technologies are currently in a dormant state but automakers are increasingly evaluating the potential of variable valvetrain applications in reducing pollutants.

Essentially, the growth of individual technologies depends upon the extent to which they enable diesel engines to fulfil certain important requirements. For instance, boosting techniques, engine management and after-treatment systems enable diesel engines to provide reduced fuel consumption and emission, increased power density and performance and diminished noise, vibration and harshness (NVH) characteristics. These advantages strongly favour such technologies.

Although valvetrain technologies exert little influence on such requirements, they are expected to play an important role in the future with emission regulations becoming progressively more stringent.

There have been considerable developments in fuel injection equipment. CRDI is fast becoming a standard feature in the diesel engines of modern passenger vehicles due to the many advantages it offers such as better combustion, improved emission control and reduced fuel consumption.

By 2012, fuel injection technologies are expected to account for the bulk of diesel engine technology revenues. CRDI and unit injector technologies along with multiple injection and variable nozzle characteristics are expected to remain the focal points of interest in the European market.

Boosting technologies have undergone similar developments, with the simple turbocharger transforming into the modern variable geometry turbocharger and double stage charging. With the specific power output of diesel engines increasing, turbochargers are now a critical part of virtually all engines manufactured today.

Although newer technologies such as homogeneous charge compression ignition (HCCI) and selective catalyst reduction (SCR) are getting a good amount of attention as the technologies likely to drive diesel engines in the future, vehicle manufacturers are still uncertain about when they can actually enter serial production.

Automakers are still struggling to understand the start of combustion in HCCI and its subsequent control. HCCI can be expected to feature in passenger vehicles in the European market only when automakers are able to properly comprehend its functioning.

Among exhaust gas after-treatment systems, diesel particulate filters are projected to significantly grow in the period 2001-2012 with penetration rates likely to reach 35% in 2010. Automakers are recognising the strong potential of DPFs with regard to particulate matter and oxides of nitrogen reduction.

At the same time, governments are offering generous fiscal incentives for vehicles equipped with DPFs. This, combined with increasingly strict emission norms, has been greatly instrumental in encouraging the adoption of DPFs and boosting their penetration rates as well as revenues in the European market.