The GT Association made a brief announcement on Monday stating that the ETS Racing Fuels-supplied CNF that was planned to be used in both classes from 2023 will not be used for the lower division for the opening two rounds of the season at Okayama and Fuji.
However, the new fuel will be used from next week's season opener as normal in the GT500 class.
A short explanation for the delay read: "Due to the wide variety of manufacturers, car models and engine types, and the time required to respond, we are extending the preparation period for the introduction [of CNF]."
Teams in both the GT500 and GT300 class have reported a minor reduction in power using the CNF during off-season testing, a consequence of the cellulose-based product not being fully burned in the combustion process.
However, the three manufacturers in the GT500 class, Honda, Toyota and Nissan, are understood to have been more advanced in their preparations, having conducted bench testing with the new fuel since last year.
Conversely, many GT300 teams were only using the CNF for the first time in last month's official Okayama test, although a handful of squads did take part in a one-day post-season test at Motegi to try out the new fuel.
42-car entry list for Okayama opener
The entry list for the opening round of the new SUPER GT season at Okayama has been released, containing 42 cars across both classes and essentially no deviations from the full-season entry list.
Fifteen cars are set to do battle in GT500, while 27 are entered in GT300, including the #25 Tsuchiya Engineering Toyota GR Supra that was damaged in a crash in pre-season testing at Fuji.
