The FIA has issued a directive for teams not to paint markings on tires for the remainder of the present ABB FIA Formula E Championship season.
The notice comes in relation to Article 25.3 of the 2018-19 Formula E Sporting Regulations which stipulates what identification can be displayed on the sidewalls of the Michelin tires.
The wording of the article simply states that ‘on the sidewall of each tyre, appropriate identification will be applied.’
Traditionally teams use the names or initials of drivers to identify individual sets of tires which are issued to car numbers for races.
E-racing365 first reported that some teams were using elaborate dot markings, such as in the above image from the Rome E-Prix, in a presumed effort for their drivers to get an optical representation of when tires were beginning to lock.
Drivers can’t feel their wheels starting to under-rotate until it gets to a certain level of locking, so a visual aid helps drivers find out when their wheels are locking sooner.
Now, it is believed that teams will only be allowed to mark the number of the car, the individual set number of the tires and the location of tires, such as front right.
E-racing365 has discovered that some teams have also put the dots on the rear tires in recent races.
This does not fit in with the theory of them being used for the primary purpose of visual identification for brake-locking and has led to question marks about the precise reasons they are actually applied to some cars.
One explanation could be that they are applied as a wheel speed measurement application that could pick up frequency of the dots and contribute to a crude traction control system.
Although unlikely, this has been used in other disciplines of racing before in which, like Formula E, traction control is not permitted.
Unsubstantiated suspicions have been rife amid several teams that a large amount of current participants have developed systems very similar to traction control within their software anyway.
Article 6.1 of the current technical regulations explicitly forbids vehicle speed measurement, and includes wheel speed measurement as an example.
However, front and rear wheel speeds are measured and available to the teams via the FIA logger, but these are known to have a time delay which often renders them obsolete for full control purposes.