Porsche North America will switch to Michelin’s 2015 WEC tire, beginning with next weekend’s Northeast Grand Prix, in an effort to help bring the GT Le Mans class cars back in contention.
A Michelin spokesperson confirmed to Sportscar365 that the pair of CORE autosport-run Porsche 911 RSRs will utilize last year’s WEC medium tire compound, as part of a Balance of Performance adjustment issued by IMSA.
The German manufacturer has struggled with Michelin’s 2016-spec tire since the tires debuted in IMSA competition at Mazda Raceway Laguna Seca in May, having failed to finish on the podium in the last two races.
Per the request of Porsche, IMSA has approved a change back to the 2015 tire, although it has come with a 20kg weight increase, which brings the cars back up to the baseline minimum weight of 1240kg that it started the season with.
The approved tire, per Michelin, is not the same compound that was run at the beginning of the 2016 season, nor is the “single-stinters” that GTLM teams utilized at Road America and Virginia International Raceway last year.
It’s understood only the medium compound tire has been changed, leaving the remainder of the tire selection for the Porsche the same as in recent races.
Other BoP changes have also been made to GTLM cars, including the BMW and Ferrari, heading into the Lime Rock race.