Here’s the last of five summaries of the decades that have formed half centurion history thus far of IMSA.

2010s

On September 5, 2012, leaders of GRAND-AM Road Racing and the American Le Mans Series shocked the racing world.

In a news conference at Daytona International Speedway, GRAND-AM Founder Jim France and President and CEO Ed Bennett joined American Le Mans Series founder Don Panoz and ALMS President and CEO Scott Atherton announced plans to merge the ALMS and the GRAND-AM Rolex Sports Car Series to form a new series to begin competition in the 2014 season.

Just prior to the start of the 2013 season, series officials announced there would be four classes in the new series.

Prototype (P) The headline class for the series would feature a mix of Daytona Prototypes from GRAND-AM and LM P2 prototypes from the ALMS. These cars would remain eligible to compete in the class through the end of the 2016 WeatherTech Championship.

GT Le Mans (GTLM) The manufacturer-backed GT class was carried over in its entirety from the ALMS, utilizing the same technical specifications as the main GTE class at the 24 Hours of Le Mans and the FIA World Endurance Championship. This class provided the backbone for a relationship between IMSA, the FIA and the Automobile Club de l’Ouest (ACO), which organizes the 24 Hours of Le Mans. The GTLM class continues to use ACO technical rules to this day.

GT Daytona (GTD) This class also featured a mix of cars with roots in either the Rolex Series GT class or the ALMS GT Challenge (GTC) class. These cars remained eligible to compete in the WeatherTech Championship through the end of the 2015 season.

Prototype Challenge (PC) The Pro-Am prototype class came over in total from the ALMS, complete with its open-cockpit ORECA FLM09 chassis powered by spec-V8 engines. PC completed its final WeatherTech Championship race in the Motul Petit Le Mans at Michelin Raceway Road Atlanta in 2017.

The P, GTD and PC classes all rode on Continental Tires, which became the Official Tire of IMSA after its previous status as the Official Tire of GRAND-AM. GTLM was open to multiple tire manufacturers.

In 2013, Chip Ganassi Racing, the most successful Daytona Prototype team in GRAND-AM history, appropriately kicked off the final season of Rolex Series competition with a victory in the Rolex 24 At Daytona on Jan. 26/27. The foursome of sports car legend Scott Pruett, multi-time Rolex Series Champion Memo Rojas, budding IndyCar star Charlie Kimball and Juan Pablo Montoya, an Indy 500, Formula 1 and NASCAR Cup Series race winner, combined to take the overall victory in Ganassi’s #01 BMW-powered Riley DP.

The #24 Audi R8 fielded by Alex Job Racing and co-driven by Filipe Albuquerque, Oliver Jarvis, Edoardo Mortara and Dion von Moltke won the GT class, while the GX class, in its only Rolex Series season, was won by Nelson Canache, David Donohue, Shane Lewis and Dr Jim Norman with the #16 Napleton Racing Porsche Cayman.

Just prior to the 2013 American Le Mans Series presented by Tequila Patrón season-opening Mobil 1 Twelve Hours of Sebring Fueled by Fresh From Florida, a new name for the series and the sanctioning body were unveiled. The series would be known as “United SportsCar” later renamed TUDOR United SportsCar Championship when TUDOR signed on as entitlement partner later in 2014. And the name for the sanctioning body? The International Motor Sports Association (IMSA), with historic roots dating back to 1969 when it was formed by John and Peggy Bishop and NASCAR founder Bill France.

The 2013 Twelve Hours of Sebring included the final Sebring appearance of the breathtaking Audi R18 e-tron Quattro race car. There were a pair of Audis in the P1 class, which ran away from the rest of the field, with Marcel Fassler, Benoit Treluyer and Jarvis, on the heels of a GT win in the Rolex 24, taking the overall victory.

Oliver Gavin, Tommy Milner and Richard Westbrook took the GT class in the #4 Corvette, with Scott Tucker, Marino Franchitti and Ryan Briscoe winning P2 in the #551 Honda prototype. David Cheng, Mike Guasch and David Ostella won the PC class with PR1/Mathiasen Motorsports, and Alex Job Racing picked up a Sebring win to go with its 2013 Rolex 24 win, this time with a Porsche being co-driven by Cooper MacNeil, Jeroen Bleekemolen and von Moltke.

For the only time in history, both the GRAND-AM Rolex Sports Car Series and the American Le Mans Series presented by Tequila Patrón competed on the same weekend at the same venue in 2013. It happened at Road America in Elkhart Lake, Wisconsin on the weekend of Aug. 9/10.

The Rolex Series headlined Saturday’s festivities with a two-hour, 45-minute race won overall and in the Daytona Prototype class by Brendon Hartley and Scott Mayer with Starworks Motorsport, with Bill Auberlen and Paul Dalla Lana taking the GT class win in the #94 Turner Motorsport BMW and Joel Miller and Tristan Nunez winning GX in the SpeedSource Mazda.

Sunday’s two-hour, 45-minute ALMS race went to Muscle Milk Pickett Racing and co-drivers Lucas Luhr and Klaus Graf (overall and P1), with Scott Tucker and Simon Pagenaud winning P2, Bruno Junqueira and Duncan Ende winning the PC class, Dominik Farnbacher and Marc Goossens co-driving the #91 Viper to its first win in GT and Spencer Pumpelly and Nelson Canache Jr. winning GTC.

The opening round of the TUDOR United SportsCar Championship in 2014, the 52nd Rolex 24 At Daytona, featured a whopping, 68-car field across the four competing classes. The overall and Prototype class victory went to Joao Barbosa, Christian Fittipaldi and Sebastien Bourdais in the #5 Action Express Racing Corvette DP.

Nick Tandy, Richard Lietz and Patrick Pilet combined to win the GTLM class in the #911 Porsche, while Jon Bennett, Colin Braun, James Gue and Mark Wilkins won the PC class in the #54 CORE autosport entry. In GTD, Bill Sweedler, Townsend Bell, Alessandro Pier Guidi, Jeff Segal and Scott Tucker took the win in the #555 Ferrari.

After Daytona Prototypes swept the first three races of the 2014 season, Tequila Patrón ESM teammates Ed Brown and Johannes van Overbeek scored the first TUDOR Championship victory for an LMP2 race car in a two-hour race alongside the GTLM class at Mazda Raceway Laguna Seca.

Brown started the race from the pole position in the #2 Honda prototype before giving way to co-driver van Overbeek, from nearby Oakland, California, who brought home a popular victory for the team. The GTLM race was won by Jan Magnussen and Antonio Garcia in the #3 Corvette.

In a separate race earlier that day for the PC and GTD classes, Mirco Schultis and Renger van der Zande won in PC, with Dane Cameron and Markus Palttala winning in the #94 Turner Motorsport BMW as Spencer Pumpelly ran out of fuel while leading on the final lap in the #45 Flying Lizard Motorsports Audi.

While GRAND-AM raced at Indianapolis Motor Speedway in 2012 and 2013, the only WeatherTech Championship race to be held to date at IMS happened in 2014 as part of the annual NASCAR Brickyard 400 weekend. Barbosa and Fittipaldi, on their way to a championship-winning season, claimed the victory for Action Express Racing in the #5 Corvette DP.

Canadian racer Chris Cumming combined with then-IndyCar racer Jack Hawksworth to win the PC class for RSR Racing, while Kuno Wittmer, also on his way to a championship, shared the GTLM victory with his #93 Dodge Viper co-driver, Jonathan Bomarito. Alessandro Balzan and Jeff Westphal won GTD in the #63 Scuderia Corsa Ferrari.

In what now has become an annual tradition, the first GT-only race for IMSA was held at VIRginia International Raceway in 2014. And somewhat appropriately, the racetrack with its signature barns dotting the landscape produced a barnburner of a finish.

The race came down to a last-lap battle between ex-F1 racer Giancarlo Fisichella in the #62 Risi Competizione Ferrari and Wolf Henzler in the #17 Team Falken Tire Porsche 911 RSR. Henzler had led the previous 12 laps, but coming to the checkered flag, Fisichella got a great run coming down the backstretch and zoomed past to take the victory for himself and co-driver Pierre Kaffer. Dane Cameron and Markus Palttala won in GTD in the #94 Turner Motorsport BMW, the third and final victory of a championship-winning season for Cameron.

Joao Barbosa and Christian Fittipaldi claimed their first of two consecutive Prototype season-long championships in 2014 in the #5 Action Express Racing Corvette DP, as well as their first of three straight Tequila Patrón North American Endurance Cup titles.

Kuno Wittmer took the GTLM championship in the final season of competition for the #93 Dodge Viper GTS-R team, while Colin Braun and Jon Bennett won the PC title in their #54 CORE autosport entry and Cameron won the GTD championship with Turner Motorsport.

Kicking off the 2015 season, Chip Ganassi Racing’s “Star Car” claimed the 53rd Rolex 24 At Daytona overall victory as NASCAR racers Jamie McMurray and Kyle Larson combined with IndyCar and Indianapolis 500 champions Scott Dixon and Tony Kanaan in the #02 Ford EcoBoost-powered Riley Daytona Prototype.

In the GTLM class, Jan Magnussen, Antonio Garcia and Ryan Briscoe gave Corvette Racing its first Rolex 24 win since an overall victory in 2001, with Mike Guasch, Andrew Novich, Andrew Palmer and Tom Kimber-Smith winning in PC and the #93 Riley Motorsports Viper GT3 fivesome of Ben Keating, Dominik Farnbacher, Kuno Wittmer, Cameron Lawrence and Al Carter winning in GTD.

One year after teaming up to win the Rolex 24 At Daytona, Joao Barbosa, Christian Fittipaldi and Sebastien Bourdais joined forces to win another of sports car racing crown jewels, the Mobil 1 Twelve Hours of Sebring in 2015. It was the first of two victories on the season for the trio, they also won the season-ending Petit Le Mans, which gave them the Tequila Patrón North American Endurance Cup and the season championship for the second straight year.

Magnussen, Garcia and Briscoe backed up their Rolex 24 win with a Sebring victory in GTLM, while Guasch, Palmer and Kimber-Smith followed suit in the PC class. In GTD, Ian James, Alex Riberas and Mario Farnbacher gave team owner Alex Job his 10th victory at Sebring aboard the #23 Porsche.

Five full-time IMSA racers claimed victories in the 2015 24 Hours of Le Mans, headlined by overall winners Earl Bamber and Nick Tandy, who joined forces with F1 driver Nico Hulkenberg, to take the overall and LM P1 class victory in the #9 Porsche 919 Hybrid. Both Bamber and Tandy also competed full-time in the TUDOR Championship GTLM class; Bamber sharing the #912 Porsche 911 RSR with Joerg Bergmeister and Tandy in the #911 alongside eventual series champion Patrick Pilet.

The GTE Pro class victory at Le Mans went to the trio of Tommy Milner, Oliver Gavin and Jordan Taylor in the #64 Corvette Racing Chevrolet Corvette C7.R. Milner and Gavin, shared the same car (which carried #4 in IMSA) for the full season, while Taylor’s regular ride was the #10 Konica Minolta Corvette DP alongside his brother, Ricky Taylor, for their father’s Wayne Taylor Racing team.

One of the better-kept secrets in motorsports history was pulled off at the now-annual “State of the Sport” presentation at Road America in 2015. WeatherTech, one of the world’s leading manufacturers of automotive aftermarket products was introduced as the new entitlement partner of what would become the IMSA WeatherTech SportsCar Championship at the beginning of the 2016 season.

Torrential rains throughout the 2015 season-ending Petit Le Mans at Road Atlanta brought about a lengthy red-flag stoppage and an early checkered flag, as well as a surprise overall winner. Tandy, Pilet and Lietz, from the GTLM class, took both class and overall honours in the #911 Porsche.

Barbosa, Fittipaldi and Bourdais wound up third overall but won the Prototype class, which also enabled them to win both the season-long and Tequila Patrón North American Endurance Cup titles. Guasch, Kimber-Smith and Palmer earned yet another crown jewel victory in PC, while Patrick Lindsey, Pumpelly and Madison Snow took GTD class honours in the race as Sweedler and Bell claimed the season title.

The 2016 WeatherTech Championship ushered in a new era of GT competition with the introduction of new technical specifications for both classes. The new specs for the GTLM class came online just as the new Ford GT, BMW M6 GTLM and Ferrari 488 made their debut.

The GTD class saw explosive growth with the adaptation of full international GT3 technical regulations. Seven different manufacturers: Audi, Ferrari, Porsche, Dodge, BMW, Lamborghini and Aston Martin competed in 2016 with all six full-time class competitors winning at least once. Aston Martin competed in three races.

Competition on the racetrack was fierce, beginning at Daytona, where just 0.034 seconds separated the GTLM race-winning #4 Corvette Racing Chevrolet Corvette C7.R shared by Gavin, Milner and Marcel Fassler from the second-place finishing the #3 Corvette of Garcia, Magnussen and Mike Rockenfeller.

Tequila Patrón ESM won the Prototype class with Brown, van Overbeek, Scott Sharp and Pipo Derani in the #2 Honda prototype, while John Potter, Andy Lally, Marco Seefried and Rene Rast combined to win GTD in the #44 Magnus Racing Audi R8 LMS GT3.

Less than two months later, the No. 2 Tequila Patrón ESM team of Derani, Brown, van Overbeek and Sharp became the first team since Doran/Moretti Racing in 1998 to sweep overall race victories in both the Rolex 24 and Mobil 1 Twelve Hours of Sebring.

For good measure, the #4 Corvette team of Milner, Gavin and Fassler also went back-to-back, taking the GTLM win one year after their #3 teammates did the same. Jeff Segal, Alessandro Balzan and Christina Nielsen gave the new Ferrari 488 GT3 its first victory in the #63 entry from Scuderia Corsa, with Colin Braun, Jon Bennett and Mark Wilkins winning PC in the #54 CORE autosport entry.

One of the most awe-inspiring race cars in recent memory, the Ford GT, made its debut in the 2016 WeatherTech Championship season-opening Rolex 24 At Daytona, but it wasn’t until Round 4 at WeatherTech Raceway Laguna Seca when the car’s full potential was realized. Westbrook and Briscoe gave Ford Chip Ganassi Racing and the new program its first victory in the final tune up prior to the 24 Hours of Le Mans.

The Prototype class victory at that event went to John Pew and Ozz Negri in the #60 Michael Shank Racing Honda LM P2 prototype. In a separate PC/GTD split race, Robert Alon and Tom Kimber-Smith won in the #52 PR1/Mathiasen Motorsports entry, with Mario Farnbacher and Riberas winning in GTD.

For the second consecutive year, a full-time WeatherTech Championship team claimed the GTE Pro class victory in the 2016 24 Hours of Le Mans, as Joey Hand, Dirk Mueller and Bourdais teamed up to take the victory in the #68 Ford Chip Ganassi Racing Ford GT, coming on the 50th anniversary of the Ford GT40’s 1966 victory at Le Mans.

In fact, the entire GTE Pro podium were WeatherTech Championship regulars, as Fisichella, Toni Vilander and Matteo Malucelli finished second in the Risi Competizione Ferrari ahead of Briscoe, Westbrook and Scott Dixon in the #69 Ford GT.

The GTE Am winners at Le Mans also represented IMSA, as Sweedler, Bell and Segal took the class win in the #62 Scuderia Corsa Ferrari 458 Italia.

At season’s end, Action Express Racing picked up its third consecutive WeatherTech Championship Prototype title, this time with co-drivers Eric Curran and Dane Cameron in the #31 Whelen Engineering Corvette DP. Milner and Gavin capped their fantastic year with the GTLM crown, and van der Zande and Alex Popow took the penultimate WeatherTech Championship PC title.

In GTD, Nielsen became the first woman to win a major professional North American sports car championship alongside co-driver Balzan in the Scuderia Corsa Ferrari.

If the 2016 WeatherTech Championship ushered in a bold new era for GT machines, the 2017 season was downright revolutionary for Prototype racing with the introduction of new Daytona Prototype international (DPi) and LM P2 race cars.

In the DPi ranks, Cadillac, Nissan and Mazda stepped to the plate in the first year of the format, which enabled major automotive manufacturers to compete in the top class with their own engines and specific bodywork alongside LM P2 race cars using spec Gibson V8 engines and chassis from one of four approved chassis constructors.

The 2017 season opened, as always, with the Rolex 24 At Daytona, where recently retired four-time NASCAR Cup Series champion Jeff Gordon added another highly sought-after accomplishment to his racing résumé, teaming up with Jordan and Ricky Taylor and Max Angelelli in the #10 Konica Minolta Cadillac DPi-V.R to win the Rolex 24 At Daytona.

Hand, Mueller and Bourdais followed their 2016 Le Mans victory with a 2017 Rolex 24 win, while the #28 Alegra Motorsports Porsche team of Michael Christensen, Daniel Morad, Jesse Lazare, Michael de Quesada and Carlos de Quesada won the GTD class and the #38 Performance Tech Motorsports team of James French, Patricio O’Ward, Kyle Masson and Nicholas Boulle claimed PC class honours

Continuing the momentum from the first year of GT3 specifications in 2016, three additional manufacturers: Acura, Lexus and Mercedes-AMG entered the GTD fray in 2017. Of the three, Mercedes-AMG was the first to break through with a victory, which came courtesy of Ben Keating, Jeroen Bleekemolen and Mario Farnbacher in the Mobil 1 Twelve Hours of Sebring.

That victory touched off a run of three straight wins for Mercedes before Katherine Legge and Lally gave Acura its first win in the Chevrolet Sports Car Classic at Detroit’s Belle Isle Park before a second straight win in the Sahlen’s Six Hours of The Glen. Lexus, meanwhile, got its first WeatherTech Championship pole position with Sage Karam at the wheel of the #14 RCF GT3 at Canadian Tire Motorsport Park.

In early July 2017, Acura Motorsports and Team Penske made official what had been rumored for quite some time, that they would be teaming up for a new, two-car DPi effort in the WeatherTech Championship beginning in 2018.

If the Penske and Acura link-up was heavily rumored, the announcement that another legendary racing organization, Joest Racing, was joining forces with Mazda, which came the week after the Penske-Acura news, was a complete surprise to most.

The Joest team is one of the most successful in prototype racing history and was looking for an opportunity to re-enter the sport after a 16-year run at the helm of Audi’s LM P1 program came to a close at the end of 2016. Joest found a willing partner in Mazda, which launched its own new DPi program in 2017, but was struggling for strong results.

Those midseason announcements briefly took attention off the racetrack and put it onto the future. However, it was a memorable first season of DPi competition, especially for brothers Jordan and Ricky Taylor, who won the first five consecutive races, including the Mobil 1 Twelve Hours of Sebring, where they followed in their father’s footsteps 21 years later as winners of both Daytona and Sebring in the same year.

The Taylor brothers finished the season as runaway Prototype class champions before Ricky moved on to join Acura Team Penske and new co-driver Helio Castroneves as part of the two-car Acura DPi team that included Juan Pablo Montoya and Dane Cameron as co-drivers of the other car.

A year after their Corvette Racing teammates won the GTLM title, #3 C7.R co-drivers Magnussen and Garcia picked up the 2017 GTLM championship, their first of two consecutive titles, while James French and Pato O’Ward became the final WeatherTech Championship PC titlists, and Nielsen and Balzan became back-to-back GTD champions.

The headlines generated in mid-2017 by Acura Team Penske and Mazda Team Joest were overshadowed in the 2018 WeatherTech Championship season by Action Express Racing. The team’s #5 Cadillac DPi shared by Barbosa, Fittipaldi and Filipe Albuquerque opened the year with the Rolex 24 At Daytona victory, with Barbosa and Albuquerque winning on the streets of Long Beach also.

Curran and team newcomer Felipe Nasr won at Detroit in the #31 Cadillac and their consistent season from start to finish netted them the 2018 WeatherTech Championship Prototype class title. Derani teamed with van Overbeek and Nicolas Lapierre in the #22 Tequila Patrón ESM Nissan DPi to win Sebring, then went on to share the team’s final victory with van Overbeek at WeatherTech Raceway Laguna Seca.

Acura Team Penske’s big moment in the 2018 sun came at Mid-Ohio, where Taylor and Castroneves led a 1-2 sweep ahead of Cameron and Montoya. The Prototype season saw a midyear flourish of victories by ORECA LMP2 machines, including a popular Sahlen’s Six Hours of The Glen win for JDC-Miller Motorsports and co-drivers Stephen Simpson, Misha Goikhberg and Chris Miller and back-to-back wins by Colin Braun and Jon Bennett, who nearly took the Prototype title themselves for CORE autosport.

Magnussen and Garcia won their second straight GTLM title on the strength of eight podium results, but no victories, becoming the first to win an IMSA title without winning a race since Craig Stanton won the GRAND-AM GT championship that way in 2005. In GTD, Bryan Sellers and Madison Snow capped a dream year for Lamborghini, which won its first Rolex 24 with the GRT Grasser Racing Team, by winning at Sebring and taking home the 2018 WeatherTech Championship GTD title.

Beginning with the 2019 season, Michelin became the new exclusive tire supplier for the WeatherTech Championship, the newly named IMSA Michelin Pilot Challenge and the IMSA Prototype Challenge for the next 10 years, as well as the entitlement of the four-race IMSA Michelin Endurance Cup.

The 2019 Rolex 24 At Daytona also launched a six-year broadcast partnership with NBC Sports that includes coverage of five different IMSA-sanctioned series this year. The rain-shortened race was won for the second time in three years by the #10 Konica Minolta Cadillac DPi squad and Jordan Taylor, who was joined by full-season co-driver van der Zande, FIA World Endurance Championship (WEC) racer Kamui Kobayashi and two-time Formula 1 World Champion Fernando Alonso.

BMW Team RLL won the GTLM class at Daytona with its #25 entry shared by Connor De Phillippi, rising IndyCar star Colton Herta and BMW factory aces Augusto Farfus and Philipp Eng, but it was the team’s #24 entry that dominated the prerace headlines with driver Alex Zanardi, a two-time Champ Car champion who competed in his first race in North America since losing his legs in a crash at Germany’s EuroSpeedway Lausitz in 2001.

At Sebring, Derani co-drove to the DPi class victory in the #31 Cadillac with Nasr and Curran, becoming the first driver since Phil Hill in 1958, 1959 and 1961 to win three Twelve Hours in four years. The Porsche GT Team of Nick Tandy, Patrick Pilet and Frederic Makowiecki won the GTLM class at Sebring for the second consecutive year, while GRT Grasser backed up its second straight Rolex 24 GTD class victory with its first win in the Mobil 1 Twelve Hours of Sebring Presented by Advance Auto Parts.

In 2019, IMSA has 19 official automotive partnerships and sanctions seven different series, the WeatherTech Championship, Michelin Pilot Challenge, IMSA Prototype Challenge, Porsche GT3 Cup Challenge USA by Yokohama, Porsche GT3 Cup Challenge Canada by Yokohama, Lamborghini Super Trofeo North America and Ferrari Challenge.

Its 12-race WeatherTech Championship schedule includes the most historic and revered road racing facilities in the U.S. and Canada, and the entry list continues to feature legendary race teams and many of the world’s best sports car racing drivers.

After 50 years, it looks like the best might yet be to come for IMSA.

Part 1: Overview – and The 1970s >>

Part 2: The 1980s >>

Part 3: The 1990s >>

Part 4: The 2000s >>