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Schaeffler bringing thermal management module to North American market; up to 4% improvement in fuel economy

Rotary slide valves controlled by sensors enable the ideal temperature window for the engine and transmission to be reached quickly. Click to enlarge.

Schaeffler is bringing its advanced thermal management system to control drivetrain temperature more precisely to the North American market. Through the proactive management of engine, transmission, hybrid component and battery temperature, Schaeffler’s Thermal Management Module improves fuel economy by as much as 4%, according to the company.

Currently in production in Europe (on Audi’s EA 888 Gen3 engine), the module also provides occupant benefits, such as a 40% reduction in internal vehicle warm-up time.

Developed as a system solution for the entire drivetrain, Schaeffler’s Thermal Management Module uses electronic sensors to control engine temperatures more accurately to reduce warm-up time, increase efficiency range from the engine to the transmission to the turbocharger, as well as improve energy efficiency and the lifespan of components.

The system integrates numerous functions in a compact assembly that is manufactured from lightweight, high-strength Polyphenylene Sulfide (PPS) plastic with fiber content.

The system replaces the traditional wax element thermostat, allowing temperature to be more precisely controlled by means of a rotary slide valve that enables the ideal temperature window for the engine and transmission to be obtained rapidly. Reacting on the driver’s power demand, the valve immediately supplies the required cooling performance. Due to an advanced calculation model, the coolant temperature stays in a range of +/- 2°C.

Precise control increases energy efficiency and the life of components by reducing friction throughout the drivetrain. According to Schaeffler, specific components can now operate at higher temperatures than would be possible with a system controlled by a thermostat, which reduces friction without loss of operational safety.

Additionally, the shortened warm-up leads to increased passenger comfort. The engine temperature can also be lowered under full load conditions, reducing knocking and fuel enrichment. Since the controlling element is an electric motor, temperature difference between part and full load is theoretically unlimited.

Applicable for engines of all sizes, the module can be adapted to any OEM requirement through the customization of the system’s sensor output signal. The standardized sensor and drive group, as well as the sealing and material technologies offer reduced R&D cost.

As a fall-back solution, a small thermostat is included in the module. Working only in off-limits conditions, it prevents engine overheating and offers appropriate limp-home function. Further, the integration of several single-purpose components into one module reduces application effort, ECU (engine control unit) complexity and assembly efforts, leading to improved system reliability.



This could become a low cost solution to get a 4% efficiency gain and extended component life time duration for ICE and future EVs. High accuracy, long lasting, rugged temperature sensors are very very cheap. Invertor type e-pumps used on new Air Cons and Heat Pumps are also very cheap.

Why wasn't that very well know mature technology used 10+ years ago?


This looks like a low reliability solution to get UP TO 4% (likely almost immeasurable) efficiency gain.

"The system replaces the traditional wax element thermostat". . "a small thermostat is included in the module." Umm, so much for low cost.

Electrical resistance temperature detectors (RTDs) require processing electronics, drive electronics and an electromechanical control valve that does not leak.

The traditional wax element (Vernatherm) thermostat is proven, used throughout the auto and aircraft industry for fuel and oil temperature control, has no leakage issues and provides sensing and actuation on one small package.

Roger Pham

The wax element thermostat almost always needs replacement before 100,000 miles, sometimes twice. It is usually the weakest link in a vehicle's reliability, which needs replacement before anything else. The inherent lag time between when high temperature occur to when sufficient coolant flow arrive to cool the engine off means that the engine's operating temp must be generally lowered, and that affect fuel efficiency.

The Schaeffler's electric thermostatic control responds even before the rise in engine temperature occur by responding to throttle input, thus ensure much more precise temperature control. Furthermore, at high loads when combustion temp. and exhaust temp. are higher, cylinder head temp can be kept cooler in anticipation, thus reducing detonation risk and allowing higher compression ratio for more efficiency, as well as higher power output. Faster engine warm up inherent in this type of electronic thermostat will lower emission and increase engine efficiency and engine longevity. A well-designed and manufactured device such as this can last the life of the car. These advantages are worth many times over the extra cost involved, which is not very much relative to the cost of the engine.

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