Enlarge / A Porsche 963, one of the four different kinds of hybrid prototype racing cars built to the LMDh rules, running in IMSA's GTP class at the 2023 Petit Le Mans at Road Atlanta in October. (credit: David J. Griffin/Icon Sportswire via Getty Images)

IMSA provided flights from Washington, DC, to Atlanta and four nights in a hotel so we could attend Petit Le Mans. Ars does not accept paid editorial content.

The crowd streamed onto the track before the race, seizing their last chance to see the brightly liveried cars up close. Daytona had been busy in January, but the crowd at Road Atlanta seemed even larger. To be honest, though, the race the fans were here to see would not be one for the ages. A 52-car grid packed into just 2.8 miles of race track promised potential trouble, and the 10-hour race saw 14 interruptions by the safety car, never getting into a rhythm. But I’m not sure that mattered much; the main draw for many in attendance that Saturday was simply seeing this new era of hybrid prototypes in person, and on that score, everyone left with smiles.

We’ve spilled plenty of pixels over the past 18 months or so delving into some of the minutiae of this new class of racing car, variously known as LMDh or GTP . Briefly, these are purpose-built racing cars, which start with a carbon-fiber spine from one of four racecar constructors and then add an engine, bodywork, and software from one of the four OEMs that participate, and then the same Xtrac gearbox, Williams Advanced Engineering lithium-ion battery, and Bosch electric motor as a way to keep development costs reasonable.

The rules purposely limit the amount of aerodynamic downforce a car can generate relative to the amount of drag it creates, and they positively encourage each car maker to give these race cars styling that calls out to their road-going products.

Enlarge / The #6 Porsche Penske 963 and the #10 Konica Minolta Acura ARX-06 run on Daytona's banking during the 2023 Roar Before the 24. With so many miles of testing completed, the Porsches are probably the favorites, but 24 hours is a long time in racing, and a lot can happen. (credit: Jake Galstad/LAT Images)

BMW provided flights from DC to San Francisco and back, plus five nights in a hotel, so we could attend Monterey Car Week. While I was there, I spoke with people from Acura and Lamborghini. Ars does not accept paid editorial content.

This past weekend saw the successful conclusion of the International Motor Sports Association's "Roar Before the 24," the series' preseason test ahead of this coming weekend's Rolex 24, a 24-hour race held each January at Daytona International Speedway in Florida. This year, the preseason test was more important than most, as there's a new kind of race car, called the GTP, competing in the Rolex 24 in 2023.

The new hybrid prototype category has attracted more manufacturer interest than we've seen in many years, with brands like Acura and Porsche building new cars to compete and others, like Lamborghini, waiting in the wings to join next year. But the biggest question is whether these new race cars will be able to make it to the end of the race. As in the larger automotive industry, supply shortages mean that spare parts are scarce, so the consequences of a crash are calamitous.

But what makes GTP—originally called LMDh—so attractive to car makers? I asked David Salters, head of Honda Performance Development, which oversees the Japanese OEM's racing activities in North America.

Enlarge / After 50 years away, Ferrari is building a works endurance prototype again. (credit: Ferrari)

Ferrari provided flights from DC to Bologna and back, plus three nights in a hotel so we could meet the 499P and drive the 296 GTS. Ars does not accept paid editorial content.

IMOLA, ITALY—After a break of 50 years, Ferrari is returning to top-level endurance racing with a new hybrid prototype race car. It's called the 499P, and in 2023 Ferrari will campaign a pair of cars in the World Endurance Championship, a series with the 24 Hours of Le Mans as its crown jewel.

As I've written before , 2023 is going to be an exciting time for fans of prototype racing. After the cubic megabucks-era of LMP1h collapsed under the weight of unsustainable budgets , the top class of the World Endurance Championship has spent a few years in the doldrums as Toyota faced minimal opposition from much smaller teams. But the Automobile Club de l'Ouest (which runs the Le Mans race) has a new ruleset now, called LMH (Le Mans Hypercar), designed to attract the interest of automakers by keeping costs sane—€30 million versus the €80-200 million that LMP1h cost—and, with less reliance on aerodynamic downforce , allowing for a closer visual link to their road-going products.

And so far, it's working. Toyota was first to LMH with its GR010 , followed by boutique manufacturer Glickenhaus, then this year saw Peugeot ease its way back into to endurance racing with its new 9X8 —still not sporting a rear wing—ahead of a full campaign in 2023. But none of those brands have quite the same magic as Ferrari. Even though it last won Le Mans outright in 1965, it still has more of those overall wins (nine) than Toyota (five) and Peugeot (three) combined, trailing just Audi (13) and Porsche (19).

Enlarge / Porsche knows the road to a Le Mans win involves tens of thousands of miles of testing. (credit: Jonathan Gitlin)

Porsche provided flights from DC to Daytona Beach and back, plus a night in a hotel so we could attend its private 963 test. Ars does not accept paid editorial content.

DAYTONA BEACH, FLA.—Car companies like to keep new models far from prying eyes during the development process. That goes doubly so when they’re going racing, like Porsche is with its new 963, which made our invitation to watch the car test on Friday, while still in development, a rare chance to watch expertise at work. Doubly so considering that Porsche's partner with the 963 is Penske Racing, an organization that has racked up more than 600 wins across a range of disciplines over the past 56 years.

The 963 has been built to win the 24 Hours of Le Mans and endurance races like it and will compete next year in IMSA's new GTP category as well as the FIA WEC's Hypercar class. Built to a rule set known as LMDh , it's more of a collaboration than the Porsche crest on the nose might lead you to expect. Multimatic in Canada provides the car's carbon-fiber spine, or chassis. Xtrac supplies the transmission, Williams Advanced Engineering provides the lithium-ion traction battery, and Bosch is responsible for the electric motor/generator unit, all three of which are tightly packaged together.

But Porsche has built the twin-turbocharged 4.6L V8, which traces its roots back to the mid-2000s RS Spyder race car, with a road-going derivative also found in the 918 Spyder hypercar. Power is capped at 680 hp (500 kW) for the internal combustion engine and hybrid system working together and is measured by sensors to ensure no one gets over-creative.

Enlarge / The new Porsche 963 sports prototype made its world debut at this year's Goodwood Festival of Speed in England. (credit: Porsche)

Last month, Porsche used the Goodwood Festival of Speed in the UK to formally debut its newest model. It's not another 911, nor a new SUV; it's a hybrid sports prototype designed to win on track here in the US and at Le Mans. You can tell the car has big shoes to fill just by looking at its name—Porsche is calling the new racing car the 963 because it's the spiritual successor to the legendary 962 that dominated sports car racing in the 1980s.

Unfortunately, Goodwood took place at the same time as my vacation at Watkins Glen in New York for IMSA's six-hour race, so Ars wasn't able to see the 963 run in person. But I was able to sit down with a pair of Porsche's factory racing drivers to find out a bit more about the new car.

Mathieu Jaminet and Matt Campbell are currently contesting the IMSA WeatherTech championship in a GT car—a Porsche 911 GT3R that started life on the same production line as the road-going 911s. But next year, the pair will be among the Porsche factory drivers who have been chosen to campaign the faster, more complex 963 here in the US or in the World Endurance Championship (WEC).

Enlarge / This is the Cadillac GTP Concept, which is our first look at what will become Cadillac's endurance racing car in North America and at Le Mans. (credit: Cadillac)

This weekend saw the annual running of the 24 Hours of Le Mans in France. It was hardly a race for the ages—don't worry, no spoilers here—but with any luck, that will change next year with the introduction of a new class of hybrid race cars (known as LMDh cars, for Le Mans Daytona hybrid) from manufacturers like Acura, BMW, Porsche, and others.

We've seen a teaser of the Acura ARX-06 , and BMW showed off a semi-camouflaged version of its new M Hybrid V8 earlier in June . Porsche's car, which started testing at the start of the year , will be formally unveiled and named later this month at the Goodwood Festival of Speed in the UK.

And on the eve of Le Mans, Cadillac released the first public images of the Project GTP Hypercar, which the company says previews the design of the car that will contest the North American IMSA WeatherTech Sportscar Championship and the global FIA World Endurance Championship (which includes the 24 Hours of Le Mans).

Enlarge / The M Hybrid V8 is instantly recognizable as a BMW, as it wears the brand's kidney grille. (credit: BMW)

On Monday, BMW became the first carmaker to reveal its new hybrid racing prototype built to the new LMDh rule set. It's called the BMW M Hybrid V8, and it will race for the first time at next January's Rolex 24 in Daytona.

Sports car racing is in the midst of a transition period as race organizers in the US and Europe adopt new rules for prototype race cars. Because we're talking about sports car racing, and because there are two sets of organizers, it's all a bit complicated.

The 24 Hours of Le Mans is organized by the French Automobile Club de l'Ouest, or ACO. Many of the cars that run in that race also compete in the World Endurance Championship, which is organized by the Federation Internationale de L'Automobile (or FIA). In the US, there's the International Motor Sports Association (IMSA), which runs the WeatherTech championship.