New to sports car racing? Here's everything you need to know about IMSA, how endurance racing works, and what makes it different from other forms of motorsport.
The IMSA WeatherTech SportsCar Championship is North America's premier sports car racing series, run by the International Motor Sports Association (IMSA). Think of it as the American equivalent of the FIA World Endurance Championship (WEC), which runs events like the 24 Hours of Le Mans in Europe.
IMSA races are held at road courses (tracks with both left and right turns) across the United States and Canada. The 2026 season features approximately 10–11 races ranging from 2.5-hour sprints to the 12-hour Sebring and 24-hour Daytona endurance classics.
Multiple classes race simultaneously. Unlike Formula 1 or NASCAR where everyone drives the same type of car, IMSA fields four different car classes — GTP, LMP2, GTD Pro, and GTD — all racing on track at the same time. A top-speed GTP car will lap a GT car multiple times during a 12-hour race. Each class competes for its own victory and championship.
It's endurance racing. Instead of 60 laps over 90 minutes, these races last 2.5 to 24 hours. That means tire management, fuel strategy, pit stop timing, and driver fatigue are just as important as outright speed. A car that leads after 6 hours can lose due to a poorly-timed pit stop in hour 11.
Three drivers per car. In the endurance events (Daytona, Sebring, Watkins Glen, Petit Le Mans), each car must have three drivers who share driving duties. In sprint races, two drivers share the car. No single driver can dominate by simply being fastest all day.
The IMSA season opens at Daytona in January with the famous 24-hour Rolex 24, then moves to Sebring in March for the 12-hour race. Shorter races at Mid-Ohio, Detroit, and VIR follow before returning to endurance events at Watkins Glen (6 hours), Road America (6 hours), and Petit Le Mans at Road Atlanta (10 hours) in October.
The five longest endurance races form a separate championship called the Michelin Endurance Cup. The Sebring 12 Hours is Round 2. Points in the Endurance Cup are awarded at the 4-hour and 8-hour marks during the race — not just at the finish. This keeps the entire race meaningful and prevents teams from cruising to the end once they have a comfortable lead.
Daytona, Sebring, Watkins Glen, Road America, and Petit Le Mans make up the Endurance Cup — a championship within a championship, rewarding the best endurance performers of the season.
IMSA and the FIA use a driver grading system to ensure fair competition between professional and amateur drivers, especially in the GT classes.
Elite professionals — current or recent top-tier single-seater or sportscar champions. The very best in the world.
Full-time professional racing drivers. IndyCar regulars, WEC factory drivers, and top GT professionals are typically Gold-rated.
Semi-professional drivers. Strong results but not racing at the highest level full-time. GTD cars must include at least one Silver or Bronze driver.
Gentleman/amateur drivers. Typically wealthy enthusiasts who fund their teams and race for the love of it. Bronze ratings allow them to compete alongside professionals.
GTP: No restrictions — all-professional lineups are standard.
LMP2: No more than one Gold-rated driver per car.
GTD Pro: No restrictions — all-professional lineups.
GTD: Must include at least one Silver or Bronze driver per car.
Points are awarded separately in each class. A win in GTD is worth the same number of championship points as a win in GTP — they just count toward different class championships.
Winning a race earns 350 points. Points scale down through the finishing order, with even last-place finishers earning some points for the championship. This means there's always an incentive to finish rather than retire.
The Sebring 12 Hours has an unusual feature: points are also awarded at the 4-hour and 8-hour marks in addition to the race finish. This is part of the Michelin Endurance Cup format and means a team that leads at hour 4 but breaks down later still earns some championship points.
The fastest qualifier in each class earns 35 points, with the second-fastest earning 32 and third fastest earning 30. Pole position matters not just for grid position but for the championship.
In addition to driver and team championships, IMSA runs separate manufacturer championships. Porsche, Cadillac, BMW, Acura, Ferrari, Corvette, and others all compete for manufacturer bragging rights across the season.
At the end of the season, the team and driver pair with the most points in each class are crowned champions. The Sebring result will heavily influence the 2026 championship standings in all four classes.
Cars must stop to refuel approximately every 1–2 hours. Teams can gain or lose positions by extending stints slightly to catch a favorable moment — like when a full-course yellow caution period is called.
Each car requires a minimum of three drivers in endurance events. Teams must manage when to swap, ensuring each driver gets adequate time and that the fastest driver is behind the wheel at critical moments.
Sebring's brutal concrete surface destroys tires quickly. Teams must decide whether to change two tires or four, balancing speed against the time cost of extra tire changes. Wrong tire calls can cost the race.
Faster GTP cars must navigate through slower GT cars constantly. GT drivers must yield cleanly. A GTP car held up in traffic for even 5 seconds per lap loses over a minute per hour — enormous over 12 hours.
When an accident or debris requires a safety car, smart teams pit immediately under the caution to avoid losing time in an open pit window later. "Pitting under yellow" is one of the most crucial strategic decisions.
The race runs from 10 AM to 10 PM, but with only track lighting, dusk and darkness present visibility challenges. Cars switch to running lights at dusk. Night practice on Thursday is critical for setup.