For the 2017 season, Porsche presented a newly developed 911 RSR. Based on the 991.2 production model, the chassis, body structure, aerodynamic concept, engine and transmission were completely redesigned. The engine-gearbox unit was reversed, transforming the 911 from a rear-engined to a mid-engined racing car. For traditional reasons, Porsche itself described the installation position as the engine in front of the rear axle, which the Porsche 911 GT1 already had. This enabled two decisive advantages to be gained: firstly, the weight distribution was improved, which benefits tire use, and secondly, there was space for the larger rear diffuser permitted in the new GTE regulations. Since the gearbox now installed in the rear was flatter than the engine, the rear diffuser could be wider and, above all, higher. To further improve the aerodynamic efficiency, the mounting of the rear wing was moved to the top of the rear wing blade in order to eliminate interfering contours and to improve the interaction between diffuser and rear wing.

The engine itself was also new. It was still a naturally aspirated engine with direct injection. Depending on the size of the restrictor, the 4.0-liter boxer six-cylinder developed around 510 hp. Contrary to the trend in the GTE class towards turbo engines, Porsche opted for the naturally aspirated engine due to the weight disadvantage of 33-88 lbs for turbo technology and the space and cooling requirements. Mated to the engine is a six-speed electronic sequential gearbox which is cased in magnesium, and is operated using steering wheel mounted paddle shifters. The fuel tank of the 991 RSR was installed in the front of the car. Instead of the previous MacPherson struts with simple wishbones, a wheel suspension with double wishbones was used on the front axle. In addition, a new cockpit and a collision avoidance system were introduced, with which the faster prototypes can be recognized early on, on a monitor in the cockpit, even in the dark.

The 911 RSR weighs just 2,720 lbs with its full arsenal of wider haunches, 13-inch-wide rear wheels and a massive rear diffuser and rear wing. Entire sections of its carbon fiber panels can quickly and easily be replaced thanks to the clever use of quick-release mechanisms. It took 4 employees 10 working days to build one 911 RSR. Porsche sold six cars to customer teams at a cost of $1.18 million plus tax each.

The Manthey Racing team achieved a double victory in the GTE Pro class at the 2018 24 Hours of Le Mans, and also won at Fuji and Sebring. The team won the FIA World Endurance Championship in the 2018–19 season with drivers Michael Christensen and Kevin Estre taking the driver’s championship. These victories as well as the points earned by Gianmaria Bruni and Richard Lietz in the 91 car earned Porsche the World Endurance GTE Manufacturers’ Championship.

In the IMSA GTLM Championship, Patrick pilot and Nick Tandy scored victories in Sebring and Road Atlanta in the 91 numbered car. Earl Bamber and Laurens Vanthoor drove the number 92 car to a victory at Mid-Ohio.