The background
The reputation of Jaguar Land Rover (JLR) has always rested on two great automotive brands that have become iconic thanks to their exceptional design and engineering capabilities. Environmental issues have driven new areas of innovation at JLR and the low-cost, start-stop device is a great example of this.

 

Engine stop-start is a technology that improves the fuel economy in passenger vehicles by enabling the engine to be turned off when the vehicle is stationary at signals and in traffic jams. The challenges in the way of this innovation were the speed of the eco-start and the noise of the restart.

 

The Belt Integrated Starter Generator (BISG), the original starting device selected as JLR’s automatic transmission stop-start enabler, was widely believed to be the only way to achieve the start time target of 350 milliseconds (msec). It was felt that the starter motor used in the 2010 Land Rover FreeLander TD4, a diesel manual vehicle, could start the vehicle no faster than the target for manual transmissions of 750msec.

 

The apparent benefits of low start time and low noise of the BISG came at a significant cost, in investment and the requirement of eight additional hardware components per vehicle.

 

The innovation
The JLR team of David Marshall, Ben Neaves, Adam Brant, Chris Carey and Andrew Senior believed that with some development the lower-cost starter motor solution could achieve a similar start time and acceptable noise performance. The JLR management directed an eight-week study into the potential of this idea, despite having already made commitments to go the BISG way.

 

Company: Jaguar Land Rover Innovation: A low-cost stop-start device Team: Adam Brant, Chris Carey, David Marshall, Ben Neaves, Andrew Senior

Working with a significant time constraint, the team conducted a feasibility study on diesel powertrains. Diesel engine start times were investigated and work started on a groundbreaking fuelling strategy that used the starter motor. The results of this study proved that the team was on the right track.

 

Meanwhile, discussions were initiated with Denso UK, a JLR supplier, to determine how a starter motor could be designed, validated and manufactured in time for the launch of the 2012 Jaguar XF, a tough timing challenge. It was necessary to have close collaboration with Denso UK in the feasibility study to enable the development of the system.

 

The breakthrough came with test confirmation that the diesel engine could indeed be reliably started and brought to its idle speed in less than 350msec, this by using a conventional starter motor, something considered impossible by industry standards.

 

Following this confirmation, the system was developed into production in a short time to support the 2012 Jaguar XF. This made JLR the first company in the automotive industry to market the stop-start feature in an automatic vehicle.

 

The payoff
Stop-start technology is designed to recover idle fuel when the vehicle is stationary. On the ‘new European driving cycle’ — employed to represent the typical usage of a car in Europe, this also assesses the emission levels of car engines — it is estimated that the fuel recovered through this feature would be approximately 8-10 percent, depending on the capacity of the vehicle’s engine.

 

On a Jaguar XF 2.2l this feature would ensure CO2 reduction of approximately 10-15g/km. This figure, multiplied by the number of vehicles sold and the distance they would cover, will ensure a positive impact on the environment. JLR can now use the technology in future vehicles.

 

For customers the development ensures improved fuel economy and vehicle range, and reduced release of CO2. For JLR the innovation promises a green, marketable technology that can ensure a big reduction in the company’s carbon footprint.