The introduction of 100% sustainable fuel to the British Touring Car Championship is only one part of a major rules revamp coming into the 2025 season.

A host of changes were ratified during an annual meeting between series organiser TOCA and all competing teams.

"Of course, the introduction of 100% sustainable fuel has been the headlining change for the 2025 BTCC season, but we always look at every aspect of our championship each year to see what can be improved," said BTCC chief executive Alan Gow.

“I’m sure that these tweaks will all have a positive effect and will further add to the great racing that is the hallmark of the BTCC.”

These changes are as follows:

Engine Specification

As from 1 April 2025, a two-year engine freeze will come into effect, so that no further developments can be made to the homologated engines for the 2025 and 2026 seasons.

This decision ensures that the highest-level of competitiveness of each engine will remain but will also significantly save costs to the teams over the next two years.

Goodyear Tyre Options

For 2025, it will be mandatory for the three overall podium finishers in Race 1 to run the hardest Goodyear tyre compound available in Race 2 – as opposed to the previous top ten finishers.

With the usual exception of Thruxton – due its high-speed nature and abrasive track surface ­– all other events will carry a standard and option tyre compound, with the latter being available to use in one of the three BTCC races.

Safety Car Procedure

A new safety car procedure will be introduced to ensure a smoother, closer and safer restart to all sessions.

When the Safety Car lights are turned off – indicating it will accelerate away from the pack and return to the pit-lane – all cars must cease weaving, braking and/or accelerating and stay no more than two car lengths from the car ahead of them.

The race leader is required to maintain approximately the same speed the safety car was using when it extinguished its lights, until the leader has passed the new ‘Restart Point’ – designated at each circuit by TOCA and to be positioned between the final corner and the start/finish control line – after which the leader can then accelerate up to racing speed.

All cars must maintain their positions, with no overtaking or overlapping until they pass the green flag at the control line.

Jack Sears Trophy

The eligibility rules for competitors in the Jack Sears Trophy have also been tweaked. Drivers that have previously won the Jack Sears Trophy and/or have scored more than one outright podium in the BTCC will not be eligible for the JST.

Qualifying Format

Grid positions for cars that do not progress from both groups in the first Part of the Qualifying session will be changed for 2025.

Those from Group 1 who do not progress into Part 2 will line up on the even numbered side of the grid and those from Group 2 on the other side – thus preventing a change in track or weather conditions having an adverse effect on those groups and their subsequent grid positions.