Editing World Solar Challenge (section)

== Important rules ==
*The timed portion of the challenge stops at the outskirts of Adelaide, 2998&nbsp;km from Darwin. However, for the timings recorded at that point to count, competitors must reach the official finish line in the centre of the city under solar power alone.
*As the challenge utilises public roads, the cars have to adhere to the normal traffic regulations.
*A minimum of 2 and maximum 4 drivers have to be registered. If the weight of a driver (including clothes) is less than {{convert|80|kg|lb|abbr=on}}, ballast will be added to make up the difference.
*Driving time is between 8:00 and 17:00 (from 8&nbsp;a.m. to 5&nbsp;p.m.). In order to select a suitable place for the overnight stop (alongside the highway) it is possible to extend the driving period for a maximum of 10&nbsp;minutes, which extra driving time will be compensated by a starting time delay the next day.
*At various points along the route there are checkpoints where every car has to pause for 30&nbsp;minutes. Only limited maintenance tasks (no repairs) are allowed during these compulsory stops.
*The capacity of the batteries is limited to a mass for each chemistry (such as Lithium Ion) equivalent to approximately 5&nbsp;kWh maximum. At the start of the route, the batteries may be fully charged. Batteries may not be replaced during the competition, except in the situation of a breakdown. However, in that case, a penalty time will apply.
*Except for the maximum outer dimensions, there are no further restrictions on the design and construction of the car.
*The deceleration of the dual braking system must be at least 3.8&nbsp;m/s<sup>2</sup> (149.6 in/s<sup>2</sup>).

=== Rule evolution ===
*By 2005, several teams were handicapped by the South Australian speed limit of {{convert|110|km/h|mph|abbr=on}}, as well as the difficulties of support crews keeping up with {{convert|130|km/h|mph|0|abbr=on}} solar vehicles. It was generally agreed that the challenge of building a solar vehicle capable of crossing Australia at vehicular speeds had been met and exceeded. A new challenge was set: to build a new generation of solar car, which, with little modification, could be the basis for a practical proposition for sustainable transport.
*Entrants to the 2007 event chose between racing in the Adventure and Challenge classes. Challenge class cars were restricted to 6&nbsp;square meters of [[Silicon|Si]] solar collectors (a 25% reduction), and later to 3&nbsp;square meters for [[GaAs]], driver access and egress were required to be unaided, seating position upright, steering controlled with a steering wheel, and many new safety requirements were added. Competitors also had to adhere to the new {{convert|130|km/h|mph|abbr=on}} speed limit across the [[Northern Territory]] portion of the [[Stuart Highway]]. The 2007 event again featured a range of supplementary classes, including the Greenfleet class, which features a range of non-solar energy-efficient vehicles exhibiting their fuel efficiency.
*For the 2009 challenge class several new rules were adopted, including the use of profiled tyres. Battery weight limits depend on secondary cell chemistries so that competitors have similar energy storage capabilities. Battery mass is now 20&nbsp;kg for [[Li-ion battery|Li-ion]] and [[Lithium polymer battery|Li-polymer battery]] (was reduced from 25 and 21&nbsp;kg in the past).
*In 2013, a new Cruiser Class was introduced. After the German team of [https://www.hochschule-bochum.de/en/ Bochum University of Applied Sciences] competed with a four-wheeled, multi-seat car, the [[PowerCore SunCruiser#Race|''BoCruiser'']] (in 2009), in 2013 a radically new ''"Cruiser Class"'' was introduced, stimulating the technological development of practically usable, and ideally road-legal, multi-seater solar vehicles.  The route took place in four stages. Final placings were based on a combination of time taken (56.6%), number of passengers carried (5.7%), battery energy from the grid between stages (18.9%), and a subjective assessment of practicality (18.9%). Since its inception, Solar Team Eindhoven's four- and five-seat [[Stella (solar vehicles)|''Stella'' solar cars]] from [[Eindhoven University of Technology]] (Netherlands) won the Cruiser Class in all four events so far.
*In the 2015 Cruiser Class regulations, the scoring formula emphasized practicality less than before. Elapsed time will account for 70% of the score, passengers 5%, grid energy use 15%, and practicality 10%.
*In 2017, solar array areas were reduced, and the Cruiser Class was changed to a Regularity Trial, with scoring based on energy efficiency and practicality.
*In 2025, to slow down the race and show that solar cars are feasible even during winter, the race was shifted by two months to the end of August. To add more emphasis on the ''solar'' aspect of the challenge, the solar collector area was also increased to 6&nbsp;m<sup>2</sup> while limiting the battery pack capacity to 11 MJ.