IMSA - Mobil 1 Twelve Hours of Sebring

The Mobil 1 Twelve Hours of Sebring stands as a cornerstone of endurance sports car racing in North America. This prestigious IMSA WeatherTech SportsCar Championship race challenges teams, drivers, and machines through a demanding 12-hour battle at Sebring International Raceway in Florida. The 2026 edition marks the 74th running of this legendary endurance race, which also serves as a round of the Michelin Endurance Cup.

Race Format and Championship Significance

The Mobil 1 Twelve Hours of Sebring pushes competitors to their absolute limits as they race from day into night. This endurance challenge forms one leg of the informal "Triple Crown" of endurance racing, alongside the 24 Hours of Le Mans and the Rolex 24 at Daytona. The International Motor Sports Association (IMSA) sanctions this key fixture in the WeatherTech SportsCar Championship calendar. The race tests both speed and reliability as teams manage driver changes, fuel strategy, and mechanical durability over the extended duration.

The Circuit at Sebring International Raceway

Sebring International Raceway measures 3.741 miles (6.021 km) and features 17 distinct turns. The facility holds the distinction of being North America's oldest permanent road racing circuit. The track opened on a former World War II training base known as Hendricks Army Airfield, and sections of the original concrete runways remain part of the racing surface today. This unique mix of asphalt and concrete creates a notoriously bumpy track surface that demands respect from every competitor.

The circuit layout combines long straights with high-speed corners and technical slow-speed sections. Many turns carry names honoring early teams and drivers who competed at Sebring International Raceway. Drivers frequently note that the demanding surface at Sebring places more stress on equipment than even 24-hour races at other venues. The challenging conditions make this 12-hour race particularly grueling for both drivers and machines.

Classes and Competitors

The IMSA WeatherTech SportsCar Championship features four primary classes at the Mobil 1 Twelve Hours of Sebring.

Grand Touring Prototype (GTP)

GTP represents the premier class of IMSA competition. These advanced prototype race cars utilize a common hybrid powertrain that captures kinetic energy from braking and stores it for later use. Manufacturers developing GTP entries include Acura, Aston Martin, BMW, Cadillac, Lamborghini, and Porsche. Each manufacturer creates its own internal combustion engine and bodywork design. The 2026 season features 11 full-season GTP entries, with teams like BMW M Team WRT fielding two BMW M Hybrid V8 cars.

Le Mans Prototype 2 (LMP2)

LMP2 features closed-cockpit prototype cars built by approved constructors. The class maintains a strong field with 12 full-season cars from 11 teams expected. New entries for the 2026 season include Intersport and Bryan Herta Autosport, adding depth to this competitive class.

GT Daytona Pro (GTD Pro)

GTD Pro showcases race cars built to FIA GT3 technical regulations. This class allows factory teams and professional driver lineups to compete. Manufacturers participating in GTD Pro include Aston Martin, BMW, Chevrolet, Ferrari, Ford, Lamborghini, Lexus, Mercedes-AMG, and Porsche. Winward Racing and Triarsi Competizione make their GTD Pro debuts in the 2026 season. McLaren returns to IMSA competition, partnering with team RLL to campaign a single 720S GT3 Evo in this class.

GT Daytona (GTD)

GTD cars also use global FIA GT3 specifications but typically feature Pro-Am driver lineups. The 2026 season includes 14 full-season GTD entries from various teams, with additional entries joining for Michelin Endurance Cup races. Notable changes include Riley moving into GTD from LMP2 and RS1 stepping up from the IMSA Michelin Pilot Challenge.

Technical Regulations and Innovations

IMSA implements specific sporting regulations for the WeatherTech SportsCar Championship. The 2026 rules introduce a "Short FCY" (full course yellow) protocol for any full course yellow within 30 minutes of the race start or within 15 minutes of a green flag restart. During a Short FCY, the pit lane remains closed unless officials convert it to a Standard FCY.

Bronze-rated drivers must now apply to IMSA to compete in GTP or GTD Pro categories. These drivers must complete the same minimum drive time as Bronze drivers in LMP2 or GTD. Teams in LMP2, GTD Pro, and GTD categories receive two additional test days for the 2026 season. All WeatherTech Championship cars feature a Leader Light System that helps fans identify car positions within their respective classes.

Heritage and Track History

Sebring International Raceway opened in 1950 on an airfield site. The first 12 Hours of Sebring took place in 1952, establishing a tradition that continues today. The track's origins as a World War II B-17 training base remain visible in the concrete sections that form part of the racing surface. These original runway sections contribute to the demanding character that defines Sebring.

The facility has hosted significant motorsport events throughout its history, including the first United States Formula One Grand Prix in 1959. Sebring served as a round of the FIA World Sportscar Championship for many years. The venue offers fans complete access to the competitor paddock and provides elevated viewing mounds around the circuit. Porsche holds the record for most manufacturer wins at the event with 20 victories. The Mobil 1 Twelve Hours of Sebring earned recognition as North America's number one race in a USA Today reader poll.

What Makes This Race Special

The Mobil 1 Twelve Hours of Sebring combines history, technical challenge, and competitive depth. The unique surface at Sebring International Raceway creates demands unlike any other circuit in North America. Teams must balance speed with mechanical preservation as the bumpy track takes its toll on every component. The transition from daylight to darkness adds another layer of complexity as visibility changes and temperatures drop.

The IMSA WeatherTech SportsCar Championship brings together multiple manufacturers and racing categories at Sebring. Prototype cars in GTP and LMP2 share the track with GT3-based machinery in GTD Pro and GTD. This multi-class format creates dynamic racing as faster prototypes navigate through GT traffic. Driver lineups often include factory professionals, experienced specialists, and developing talent, creating a diverse field of competitors.

The endurance format tests every aspect of race team operations. Engineers must optimize setup for both daytime heat and nighttime conditions. Strategists balance fuel consumption, tire wear, and driver stint lengths. Pit crews execute quick service stops under pressure. The 12-hour duration means that consistency and reliability matter as much as outright speed. Small mistakes compound over time, while strong execution throughout the race brings success.