Red Bull's fuel partner ExxonMobil has introduced chemicals it has not used before in Formula 1 for a new, more powerful fuel it will debut at the Japanese Grand Prix.
As part of an effort for Red Bull engine supplier Honda's home race at Suzuka, ExxonMobil has made use of cutting-edge molecular science to perfect a blend of fuel that has been specifically designed for the manufacturer's Spec 4 engine.
The company's global motorsport technology manager David Tsurusaki said development work on the new fuel has taken place over several years, and included the sourcing of new "raw materials" to help achieved a breakthrough.
Asked by Autosport if this meant using chemicals that were new to F1, Tsurusaki said: "The FIA standard is pretty restrictive.
"It has to be chemicals that have been used and available in a consumer fuel in the past, so in a sense it is not brand new technology.
"But it is something that we have not used in a Formula 1 fuel, and I don't know if anyone else has done it.
"There are two or three key adjustments we have made that give us the performance enhancement we are looking for."
While Tsurusaki did not detail what power gains the new fuel is expected to offer, he said it was "one of the biggest steps" ExxonMobil has made since it starting working with Red Bull in 2017.
"And with mature engine technology, it is harder and harder to make that adjustment," he added.
"It [the upgrade] is something that we have been thinking about and working on for quite a long time. I think it is one of our better improvements.
"[But] I cannot comment on the performance gain. I know what it is, otherwise we wouldn't be introducing it, but it definitely is an improvement and wouldn't be introduced if it wasn't."
Get unlimited access to the world’s best motorsport journalism with Autosport Plus