Thanks to the Global Positioning System (GPS) tracking system used in the WRC since 2002, teams and crews have access to far more data about the performance of their cars on rally stages now than ever before:

The latest system generates split times for each car, typically at 5km intervals throughout each timed section, which can be analysed to show where time was made or lost, relative to other competitors.

The GPS data is so fast and accurate that SWRT drivers are able to receive 'almost live' updates on their progress through the stage so they can push harder, or ease off as appropriate.

At the Subaru World Rally Team, split times of all competitors are sent directly to a computer located in the management room in the service area. Sporting director Luis Moya monitors the times and informs team co-ordinator Ken Rees of the difference between the Subaru driver and his closest rival or event leader.

Ken types the appropriate split time message into another computer, linked by radio to a display screen at the co-driver's feet in the rally car. Once the message flashes up, the co-driver will inform the driver at the next suitable opportunity.

The Subaru team aim to get the split information to the co-driver less than eight seconds after it first appears on the team computer.

The message is sent in a form of shorthand using driver initials, numbers and a plus or minus sign depending on whether the Subaru driver is slower or faster. For instance, -2 CS would mean that Carlos Sainz was two seconds slower at the split point.