Land Rover’s e-Terrain concept showcases new environmental initiatives

An increasing emphasis on diesel power is clearly important to overall CO2 reductions, and bio-diesel capability extends the potential advantages. Bio-diesel is a fuel derived from renewable and sustainable sources, such as natural oils from soya beans or other easily cultivated vegetable or cereal crops. It is currently commercially available as a blend of bio-derived diesel and petroleum-derived diesel, in varying proportions, and bio-diesel offers reduced emissions compared with petroleum-derived diesel.

Currently, a five per cent bio-derived content is typical with forecourt diesel. Potentially, a vehicle could operate on a 25 per cent bio-diesel mix, which is a realistic goal within a few years, and one supported by the oil industry and governments. A vehicle running on 25 per cent bio-diesel mix could potentially reduce its CO2 emissions by up to 25 per cent. Next generation bio-fuels made from crop wastes are also being developed, and these will deliver even greater CO2 reductions, as well as being more sustainable.

Other important technologies can make a difference

Beyond the efficiency-enhancing drivetrain technology, the Land_e showcases other fuel saving technologies.

The ITP Intelligent Thermal Programme controls engine parameters including exhaust heat management and cooling system function. Through heat exchangers, the EHRS (Exhaust Heat Recovery System) utilises what is normally wasted heat from the exhaust system to promote faster engine and gearbox warm-up from cold, with several advantages. In a production application, ITP could also control Active Aero Vanes, which would allow specific sections of the radiator aperture to be closed under certain operating conditions. That would reduce high-drag airflow through the radiator core and engine bay when cooling air is not needed – for instance at low ambient temperatures and when running in low-load conditions. The vanes would also be closed during engine warm-up, again to ensure that the engine reaches optimum operating temperature as quickly as possible. Faster engine and catalyst warm-up significantly reduces emissions in the first minutes after a cold start, and by bringing engine and gearbox oils up to operating temperature more quickly, it reduces mechanical frictional losses.

An electronically controlled thermostat and cooling circuit give far more accurate control of coolant temperature than a conventional system, allowing the engine to run closer to its optimum temperature. The system also incorporates an electric water pump, which, unlike the conventional belt-driven water pump, is driven only on demand, and at variable speeds, avoiding inefficient and unnecessary overspeed running. Mechanical energy savings, optimum temperature control and fast warm-up from start offer the potential for additional CO2 emissions benefits.

Significant benefits are also possible with the use of electric power steering technology, EPAS (Electric Power Assisted Steering). EPAS completely eliminates the pumped hydraulic assistance of a conventional system and powers the steering rack directly, by electric servo motor. That eliminates pumping power losses, including the significant losses when the pump is being driven at high speed even though assistance is not required, again offering a noticeable CO2 benefit compared to a belt-driven hydraulic system. The higher-voltage electrical supply made possible by ISG also allows the possibility of more powerful assistance for more demanding use – on off-road terrain, for example.

All electrical system functions are controlled by IMES (Intelligent Management of Electrical Systems), with further efficiency gains. It incorporates a closed-loop system that monitors battery charge, vehicle electrical system demands, and generator speed and load. It uses the monitored data to ensure that the whole electrical system operates in the most efficient way. It charges the battery only when it needs it, avoiding the over-charging associated with ‘non-intelligent’ systems, and unless it is absolutely necessary, it avoids charging the battery when it is in ‘low-acceptance’ states – such as cold ambient conditions, below around 10 degrees C. It also regulates high electrical loads until the alternator is operating at high efficiency, which gives a further reduction in CO2 emissions.