The French firm made the shock announcement on Wednesday, signalling the end of its relationship with Nissan and the works NISMO team, which it has supplied continuously since the 2013 season.
A brief statement said that the decision was taken as a result of Michelin "reconsidering its race support structure".
Michelin clarified that its supply of the #23 NISMO and #3 NDDP Racing Nissan Zs, which sit first and second in the point standings, will remain unaffected until the conclusion of the current season.
The statement made no mention of plans to curtail its involvement in the GT300 class, where it supplies the Team Studie BMW M4 GT3.
Michelin's surprise withdrawal is set to leave SUPER GT's top class with three tyre suppliers in the form of Bridgestone, Yokohama and Dunlop for the first time since the 2008 season.
Yokohama, like Michelin, currently supplies two cars - the Racing Project Bandoh Toyota GR Supra and the Kondo Racing Nissan - while Dunlop supplies only one, the Nakajima Racing Honda NSX-GT.
Michelin has won four GT500 titles, two with the MOLA Nissan squad in 2011-12 and then two more in 2014-15 with NISMO.
What Michelin's exit will mean for Nissan and Super GT
Michelin’s departure has wide-ranging ramifications for both Nissan and the championship as a whole. Nissan has the headache of trying to reach an agreement with one of the three remaining GT500 suppliers, while the tyre war that has been a core element of the premier category for so many years now faces an uncertain future.
Realistically, NISMO will want to have its cars using tyres that the Nissan stable already has knowledge of. That narrows down the choice to Bridgestone and Yokohama, which currently supply Team Impul and Kondo Racing respectively.
Bridgestone seems like the obvious way to go as the dominant tyre manufacturer in GT500. NISMO previously used Bridgestone tyres from the start of its works operation in the 1990s all the way until 2009, and again from 2011-12 before the switch was made permanently to Michelin starting in 2013 after what might be called a ‘trial’ season in 2010.
But there’s a catch - Bridgestone already supplies 10 of the 15 GT500 cars in the field, up from nine last year. The Japanese firm is already thought to have baulked at supplying that many, and was only placated by ARTA sacrificing its Bridgestone-shod GT300 entry to get its new-for-2023 second GT500 car on the benchmark rubber.
Nissan has no Bridgestone users in GT300 it can offer up, and while it does have a car in GT500, is it really worth risking the ire of fans and sponsors alike by instigating the end of a decades-long relationship between Bridgestone and Kazuyoshi Hoshino’s legendary Impul team?
In order for a NISMO-Bridgestone reunion to become a reality, co-operation is likely going to be needed from Nissan’s rivals. The key player here is Toyota, which has five of its six GT500 cars on Bridgestones and (indirectly) three GT300 cars. It’s not inconceivable that one or more of these could be ‘convinced’ to switch tyre suppliers, but it’s not exactly likely either.
And so, that brings us on to the alternative: Yokohama. On paper, it doesn’t look like a great match; no car has won a race in the GT500 class using ‘Yokos’ since 2016. But that would be to overlook the strong progress that Kondo Racing in particular has made recently.
After years of struggling with the GT-R, the switch to the Z seemed to be a gamechanger for Yokohama, which arguably had the pace to win last year at Autopolis and only lost out due to a strategic faux-pas on the part of the Kondo crew. Just last week at Fuji Speedway, the #24 car shared by Kohei Hirate and Daiki Sasaki was running third and looked good for second until Hirate came a cropper in GT300 traffic with a handful of laps to go.
Granted, the Yokohama is still a way off being a competitive package at all tracks, but having three Zs sharing the same tyre would surely only accelerate development - not to mention the benefits for Yokohama of getting the feedback of a team with ample working knowledge of Michelins.
For Super GT as a whole, it would be preferable if NISMO ended up with Yokohama rather than Bridgestone. The Michelin-NISMO axis has provided an important counterweight to Bridgestone dominance over the past decade, and something similar is needed if the GT500 class is to maintain its reputation as a platform for genuine tyre competition going forward.
Losing the world’s largest tyre brand from GT500 is bad enough, but if Bridgestone was to end up with a total monopoly on what might be considered the 'top' teams, then Super GT’s upper division would be in danger of becoming a single-tyre class in all but name.
Whatever happens, Michelin will be missed. On top of its four GT500 class titles, it showed last year its strength in mixed conditions with its innovative ‘intermediate’ wet tyre, prompting its rivals to come up with new solutions of their own. That prowess was again on display at Okayama last month, where the two NISMO Zs took a 1-2 in terrible conditions.
The fact Michelin looks set to continue in the GT300 class, where it currently supplies only the Studie BMW team, is small consolation.
