Air management is more than simply just intake and filtration

Stuttgart, September 2014 – Air management? The importance of fuel management for combustion engines is well-known. Equally important are the conditioning and control of the air supply in the combustion chamber as well as the use and guidance of the exhaust gases. MAHLE is the leading provider of innovative components and systems for the complete air section.

Automotive air management covers firstly the air section from the unfiltered air intake through filtration to intercooling and the intake module. Downstream of the combustion chambers comes next the turbocharging system, with the exhaust gas turbocharger as well as controls and temperature management for exhaust gas recirculation. Further growing demands on the combustion engine create a need for the appropriate answers.

Air filtration and guidance

Optimised air management begins with the targeted, map-controlled charge motion of the incoming air. The intake pipe actuators from MAHLE provide good mixture turbulence in engines with four valves per cylinder, thus improving exhaust gas emissions and partial-load consumption.

The high-performance filters from MAHLE prove their worth at the start of the air section. They achieve high filtration performance, especially in respect of the particle retention efficiency. To ensure their long-term, smooth performance, all filters should be replaced according to the replacement intervals specified by the vehicle manufacturer. To prevent the filter from being damaged during maintenance and replacement, MAHLE equips its filters, for example for commercial vehicles, with additional safety elements in the form of special non-woven cylinders, to protect the clean side of the filter element.

These innovative air management technologies are combined with light, flexible, dirty and clean-air guides from MAHLE. They are ideally fitting for difficult installation and removal conditions during servicing. As an environmentally friendly alternative to petroleum-based plastics, MAHLE has recently validated a bio-based plastic as ready for series production of air guides.


In the meantime, an essential contribution to the efficiency and dynamics of modern combustion engines comes in the form of turbocharging. Turbochargers from Bosch Mahle Turbo Systems guarantee not only an outstanding torque curve but also high engine output, and are indispensable when it comes to complying with ever stricter emissions limits. Apart from truck turbocharger applications, passenger car turbocharger applications in original equipment quality receive noteworthy coverage in the MAHLE Aftermarket product portfolio.

In order to regulate the boost pressure of the turbocharged engine, MAHLE uses an electric wastegate actuator alongside a conventional pneumatic actuator. Thanks to this new technology, the wastegate actuator can reach any desired position in a flash, regardless of negative or positive system pressure. Its high clamping force ensures minimal leakage and consequently rapid boost pressure build-up, with the result of a very spontaneous responsiveness. The second generation of these small but effective actuators already went into series production in 2013.


As the degree of turbocharging increases, the necessity of cooling the compressed air grows. MAHLE took these increased cooling demands into consideration and developed indirect, cascaded intercooling, integrated into the intake pipe, in which two coolant circuits are configured sequentially. The system first cools the charge air through the engine's high-temperature coolant circuit; the cooled air then goes through a low-temperature circuit.

The advantages of this layout are evident:

• The cooling capacity of this two-stage process is so high that the charge air temperature virtually reaches the level of the low-temperature coolant.

• The integration of the indirect intercooler into the air intake module reduces the pressure drop by up to 80 per cent in comparison with direct intercooling.

• The large-volume charge air hoses used for direct intercooling are replaced by much thinner coolant lines. Together with the integration of the indirect intercooler into the air intake module, the packaging is thus significantly simplified.

In petrol engines, integrated cascaded intercooling produces fuel consumption savings of up to five per cent under full load. Alternatively, it is possible to increase performance at a constant fuel consumption rate. Moreover lower emissions and overall better responsiveness can be anticipated at partial loads. With this new technology, MAHLE has demonstrated noticeable consumption improvements in diesel engines under full load.

Intelligent exhaust gas recirculation

A further, fundamental actuator for the ventilation of the engine is exhaust gas recirculation (EGR). By recirculating the correct amount of combusted exhaust gas to the combustion chamber, the raw emissions produced by the combustion can already be reduced. However, this requires quickly and precisely controllable regulating devices with high actuating forces—such as the EGR valves from MAHLE.

EGR offers high potential, particularly for petrol engines, as the introduction of the WLTC (Worldwide harmonized Light duty driving Test Cycle, successor to the New European Driving Cycle (NEDC)) will require compliance with stringent emission regulations across the operating map. The answer from MAHLE entails a combination of high- and low-pressure EGR with optimised MAHLE heat exchangers and EGR valves.

Customised solutions

In addition, MAHLE offers other products and systems which, although integrated into the air guidance, are not active in every aspect of air management. With their sophisticated functionality and appearance, they fulfil a variety of requirements, sometimes emotional ones, relating to the acoustics or the design of the powertrain. They include, for example, sound generators and resonators from MAHLE, which ensure a dynamic, characteristic sound, especially in turbocharged engines. MAHLE fulfils visual requirements with attractive yet functional engine and cylinder head covers made from plastic. They can either be integrated in the intake system or also have a separate functional or design element. Crankcase ventilation vents reliably clean the gases contaminated with oil mist from the crankcase. And MAHLE blow-by heaters, based on PTC technology, are used in air and blow-by lines in order to prevent icing.

MAHLE also supports these modern technologies in the aftermarket, and thus ensures optimised filling of the engine, even after years. Both printed and digital product catalogues offer a quick overview of the Aftermarket product range in original equipment quality. To make sure that the right product is correctly installed, the repair shop can rely on a comprehensive MAHLE service portfolio. Web-based technical information leaves no question unanswered. The damage brochures from MAHLE are a “classic” example. They clearly illustrate damages to turbochargers or air filters and their peripherals in both words and pictures, and provide solutions. Product-specific fitting instructions, technical training, and the appropriate repair shop equipment from MAHLE all ensure a correct and professional repair. This is how—together with a dense network of service and sales partners—we are able to provide a continuous product and problem-solving chain. MAHLE—the expert solutions provider for the aftermarket.


MAHLE is the globally leading manufacturer of components and systems for the internal combustion engine and its peripherals as well as vehicle air conditioning and engine cooling. In 2014, some 64,000 employees at 140 production locations and ten major research and development centres are expected to generate sales of around EUR 10 billion.

About MAHLE Aftermarket

MAHLE Aftermarket, the business unit specialising in spare parts and service, uses the expertise from the series production of original equipment in its automotive aftermarket product range, and supplies trade, repair shop, and engine repair partners. MAHLE Aftermarket is represented at 23 locations and other sales offices worldwide, with 1,670 employees. In 2013, the business unit achieved a global sales volume of EUR 805 million.

Find out more about MAHLE Aftermarket GmbH