An enforcement of hybrid unit safety measures effective from last weekend's Acropolis Rally could increase costs for World Rally Championship teams moving forward.
Since the introduction of hybrid power to WRC Rally1 cars in 2022, engineers have been able to reset shock errors on the Compact Dynamics designed unit if they go above a certain threshold.
However, from last weekend, the hybrid unit user guide, in place since its inception, will now be enforced for the remaining rounds of the season if a unit exceeds a stipulated number of shocks.
If a hybrid unit suffers three shock errors over 15G or one over 25G it now has to be stripped apart and sent back to Compact Dynamics for a full repair that can take months to complete.
The user guide has been enforced on safety grounds because some units have received "a lot of shock errors," according to FIA road sport director Andrew Wheatley.
There have been concerns raised that teams could be forced to buy new units to add to their pool should any of their hybrid units require a full repair.
"What's changed in the user guide is that up until the last rally in Finland, if it [the unit] went over [the threshold] the engineer on site would just automatically wipe the errors and go again, pretty much, no matter what had happened to it," said Wheatley.
"Now what they've [Compact Dynamics] identified is that if it goes three times over 15[G] or one time over 25 [G] it has to be stripped apart. You can't just clear it and off it goes."
Asked if teams may be required to outlay more money moving forward, Wheatley added: "I think they certainly [will have] have to juggle.
"Once they've [the units] got three shocks they need to be inspected and it's a big job. Inspecting them is not just opening the top and checking inside you have to go into the battery, and that's really destructive.
"It depends on where they are in the build cycle but it can be [months before they can repaired]. You have a problem [if you don't have a lot of units], so that is why they [the teams] want to balance.
"Actually, most of them [the shock errors] come from either where there's a tyre off, or a damper is broken. [Kalle] Rovanpera's [spectacular crash in Finland] is fine because you've dissipated the energy."
Motorsport.com understands the implementation of the user guide has played a role in determining the use of a non-hybrid M-Sport Ford Puma for Martins Sesks at Rally Chile later this month.
It is expected that the matter will be discussed at the WRC Commission on Wednesday, with Wheatley revealing there could be further changes to the user guide.
"Now, where we are with Compact Dynamics at the moment, it's a constant evolutionary process backwards and forwards all the time," he added.
"There were three people here [in Greece] collecting data from every stage, every activity, sharing it with the guys from FIA and working through where the challenges are, where the opportunities are, and I think we will have more evolution of these discussions.
"There will be more versions of the user manual. The advantage of the regulation is you can change it when you have a problem. It's about the supplier deciding at what level they are prepared to accept liability."
