The Four Racing Classes

What Are GTP Cars?

GTP cars are purpose-built hybrid-electric racing prototypes — closed-cockpit (roof over the driver's head) racing machines designed from scratch to go as fast as possible, not based on any road car. They use a combination of an internal combustion engine (typically a turbocharged 4–6 cylinder or V8) plus an electric motor/battery system — the same hybrid technology pioneered in road cars, applied to racing.

The "GT" in GTP is a historical naming convention — these are pure prototypes, not GT (grand touring) cars in the modern sense. The "P" stands for Prototype.

The LMDh Connection

GTP cars are built to the LMDh (Le Mans Daytona h) specification — a set of rules created jointly by IMSA and the FIA (the global motorsport governing body). An LMDh car like the Porsche 963 can race in IMSA's GTP class one weekend and the FIA WEC's Hypercar class at Le Mans the next. This "convergence" of international regulations created the richest prototype grid in decades.

This is why you'll see the same Porsche, BMW, Cadillac, and Acura cars at both Sebring and Le Mans.

One Car for Everyone

Every LMP2 entry runs the ORECA 07 chassis with a Gibson 4.2L V8 engine — no exceptions. This "spec" approach means the cars are completely identical mechanically. The only allowed customization is livery (paint scheme) and minor aerodynamic trim adjustments within tight limits.

The ORECA 07 is an open-prototype (open-cockpit) design producing approximately 420 horsepower and can lap Sebring several seconds per lap slower than a GTP car. But it's incredibly driver-dependent — with identical cars, the best driver wins.

The Driver Rule

LMP2 has an important restriction: no more than one Gold-rated driver per car. This prevents fully factory-professional teams from stacking all their best drivers into one car. It creates a true semi-pro class where one professional acts as the "anchor" alongside Silver and Bronze-rated co-drivers.

This makes LMP2 the proving ground for rising professionals and serious amateurs. It's also the path to Le Mans for many teams — the same ORECA 07 races in the LMP2 class at the 24 Hours of Le Mans in June.

What is GT3?

GT3 is a global racing specification managed by the FIA. Manufacturers build "GT3 versions" of their high-performance road cars — adding a roll cage, fire suppression system, adjustable aerodynamics, and racing-spec tires while keeping the basic shape and engine character of the road car. A GT3 Ferrari 296 looks like a Ferrari 296, just with a giant wing and racing slicks.

GT3 is intentionally designed to be equal across manufacturers. Through a Balance of Performance (BoP) system, IMSA adjusts power, weight, and downforce for each car to keep them competitive against each other. This means a Lamborghini can genuinely beat a Porsche.

GTD Pro vs GTD

GTD Pro was introduced in 2022 to separate the factory-backed all-professional programs from the gentleman-driver GTD class that uses the same cars. GTD Pro teams typically have full manufacturer support, factory drivers, and unlimited budgets. GTD teams may have some manufacturer support but must include at least one amateur driver.

The same car — say, a Porsche 911 GT3 R — can appear in both GTD Pro (with factory aces Thomas Preining and Klaus Bachler in #911) and GTD (with gentleman driver Patrick Lindsey in #912). Same car, very different context.

The Gentleman Driver Tradition

GTD is the direct descendant of motor racing's oldest tradition: wealthy enthusiasts funding and driving their own cars in professional competition. In the 1950s, gentlemen drivers regularly raced alongside factory professionals at Le Mans and Sebring. GTD preserves this tradition in the 21st century.

A Bronze-rated driver (amateur/gentleman) might be a successful dentist, a tech company CEO (George Kurtz of CrowdStrike in LMP2, for example), or someone who simply loves racing and has the resources to pursue it professionally. They train seriously, take coaching, and genuinely compete — they're not just passengers.

Who's in GTD in 2026?

The 19-car GTD field is the most diverse and entertaining class in the field. Notable drivers include:

• Rubens Barrichello — F1 legend, 326 GP starts, in the #27 Aston Martin
• Logan Sargent & Callum Ilott — two recent F1 graduates now in the #120 Porsche
• Winward Racing — seeking a third straight Sebring GTD class win
• Brendan Iribe — co-founder of Oculus VR, driving a Ferrari