Several Formula E teams have been using specific markings on the inner sidewall of their front tires in recent races leading to speculation that they are aiding drivers’ optical perceptions when braking.
The markings are believed to have first appeared at the Hong Kong E-Prix in March and are understood to have been used by several teams.
Sebastien Buemi’s Nissan e.dams car ran with brightly highlighted, evenly sized yellow boxed on the inside of the front sidewalls at last weekend’s Rome E-Prix.
Several theories have been speculated upon as to why these have appeared, including that they provide an optical aid for drivers to see tire rotation and locking.
The Gen 2 cars incorporate an semi-encompassing front bodywork section which gives the drivers a more reduced view compared to the Gen 1 cars.
Although not mandatory, teams are allowed to measure tire temperature or pressure provided they can, according to the regulations, ‘install the sensors without modifying spec homologated parts.’
The technical regulations state: ‘If these sensors are used, there must be at least one warning light to notify the driver of a possible failure. If fitted, data must be sent to the FIA logger by CAN (Controller Area Network).’
When contacted by e-racing365, a Michelin spokesperson stated that, from its side, the markings were simply used so that “each driver doesn’t have the right to use the tires of his teammate (each tire contains a chip). So for him the yellow points are just for recognizing them.”
Audi and Jaguar are also believed to have used similar markings to help drivers with visual identity of tires locking up in recent races.
Theoretically, additional optical rotational speed sensors could contribute to a crude form of traction control.
This though would mean that an optical rotational speed sensor would have to be placed in the nose of the car facing the inside of the tire to measure the wheel speed.
However, under Article 6.2 of the current Technical Regulations, ‘the use of traction control is forbidden’ and ‘any vehicle speed sensor is forbidden’ (wheel speed, radar, GPS, pitot, etc.).
If sensors were allowed to be freely used then sensor feedback could even be used to optimise the regen of the car, again as a function of the speed delta between the rears and the fronts.
Intimately understanding the speed and movement of the front wheels can have a plethora of advantages when it comes to optimising the cars dynamics.