IndyCar Series (Johnsonverse)

The IndyCar Series, currently known as the NTT IndyCar Series under sponsorship, is the premier level of open-wheel racing in North America. Its parent company began in 1996 as the Indy Racing League (IRL), which was created by then Indianapolis Motor Speedway owner Tony George as a competitor to CART. In 2008, the IndyCar Series merged with CART's successor, the Champ Car World Series. The series is self-sanctioned by its parent company, INDYCAR, LLC., which is owned by Johnson Industries.

The series' premier event is the Indianapolis 500.

Series name
For 1996–1997, the series was simply referred to as the Indy Racing League. For 1998–1999, the series garnered its first title sponsor, and was advertised as the Pep Boys Indy Racing League. In 2000, the series sold its naming rights to Internet search engine Northern Light, and the series was named the Indy Racing Northern Light Series.

The IndyCar Series name was officially adopted beginning in 2003, as the series was now legally entitled to use it due to the expiration of a 1996 legal settlement with CART. The series began to progressively downplay the former IRL name, changing its name to simply IndyCar for the 2008 season. Izod was announced as the series title sponsor beginning on November 5, 2009. Izod ended its sponsorship after the 2013 season.

In 2014, Verizon Communications became title sponsor of the series through 2018. In January 2019, it was announced that communications company NTT would become title sponsor and official technology partner of the IndyCar Series.

Car history and current specifications
The IndyCar Series allows manufacturers to develop different types of engines and chassis. Currently, Dallara, Panoz, Stohr Cars, and Swift Engineering provide chassis to all teams, with several larger teams such as Chip Ganassi Racing, Team Penske, and Andretti Autosport designing and building their own chassis, while Chevrolet, Ford, Dodge, Toyota, Honda, Mercedes-Benz, and Oldsmobile provide teams different engines.

1996–2011
In the series' first season (1996), 1992 to 1995 model year CART chassis built by Lola and Reynard were used. The first new Indycar came into being in 1997. Tony George specified new technical rules for less expensive cars and production-based engines. The move effectively outlawed the CART chassis and turbocharged engines that had been the mainstay of the Indianapolis 500 since the late 1970s.

Starting with the 2003 season, the series rules were changed to require chassis manufacturers to be approved by the league before they could build cars. Prior to that, any interested party could build a car, provided it met the rules and was made available to customers at the league-mandated price. In total, four manufacturers had built IndyCar chassis up to that point.

Dallara began producing Indycars for the 1997 season. The Dallara and G Force chassis were relatively evenly matched over their first few seasons, but eventually, the Dallara began to win more races. This caused more teams to switch to the Dallara, further increasing their success. As of 2017, a Dallara chassis has been used by 17 Indy 500 winners, although there have not been any competing manufacturers since 2008. Dallara was also tabbed to build the Firestone Indy Lights machines. After the withdrawal of factory support from Panoz Auto Development, they were the only supplier of new chassis.

The G Force chassis was introduced in 1997 and won the 1997 and 2000 Indy 500 races. In 2002, Élan Motorsport Technologies bought G Force, and the chassis was renamed "Panoz G Force", and then shortened to "Panoz" in 2005. In 2003 a new model was introduced, and it won the Indy 500 in 2003–2004 and finished second in 2005. It fell out of favor starting in 2006, and by then, only one finished in the top ten at Indy. Little factory support was given to IndyCar teams by Panoz after that point, as they had concentrated on their DP01 chassis for the rival Champ Car World Series. By 2008, only one Panoz saw track time, an aborted second-weekend effort at Indy, that resulted in Phil Giebler being injured in a practice crash.

Riley & Scott produced IndyCar chassis from 1997 to 2000. Their initial effort, the Mark V, was introduced late in the 1997 season, severely limiting its potential market. It also proved to be uncompetitive. After Riley & Scott was purchased by Reynard, an all-new model, the Mark VII, was introduced for the 2000 season. It won in Phoenix, the second race of the season (driven by Buddy Lazier), but was off the pace at Indy and was quickly dropped by its teams.

Falcon Cars were founded by Michael Kranefuss and Ken Anderson in 2002 as the third approved chassis supplier for the 2003 season. One rolling chassis was completed and shown, but it was never fitted with a working engine and never ran. No orders were ever filled. Superficially, IndyCar machines closely resemble those of other open-wheeled formula racing cars, with front and rear wings and prominent airboxes. Originally, the cars were unique, being designed specifically for oval racing; for example, the oil and cooling systems were asymmetrical to account for the pull of liquids to the right side of the cars. Later cars were designed to accommodate the added requirements of road racing.

Because of a schedule conflict, the Champ Car World Series spec Panoz DP01, with a Cosworth engine, was run in an IndyCar Series points event in the 2008 Toyota Grand Prix of Long Beach.

2012–2014
In 2012 the series adopted the Dallara IR-12 chassis as a cost control method, and IndyCar negotiated a price of $349,000 per chassis. The new specification also improved safety, the most obvious feature being the partial enclosure around the rear wheels, which acts to prevent cars ramping up over another vehicle's back end.

This chassis was intended to support multiple aerodynamic kits, but introduction of these was delayed until 2015 with teams citing costs.

2015-2017
In 2015, teams began running aero kits developed by their engine manufacturers. The kits, while increasing speeds and offering a clear distinction between the two manufacturers, did lead to significant cost increases. Further, Chevrolet's aero kit was the more dominant with Honda only able to mount a competitive charge on ovals due to having slightly better engine power. While Honda was able to make gains in 2016, after two years of development the kits were frozen for 2017, and starting in 2018 all cars ran the same aero package again. To further help reduce costs, IndyCar allowed teams to shop for competitively priced non-safety-related parts such as brakes instead of mandating parts from specific suppliers.

IndyCar had hoped to set a new speed record at the Indianapolis Motor Speedway by 2016 with the introduction of aero kits and the development work associated with them. However, after a series of safety concerns during practice for the 2015 Indianapolis 500 with the Chevrolet aero kit package, this did not come about.

After the events of the 2011 IZOD IndyCar World Championships the chassis was nicknamed DW12 in honour of Dan Wheldon.

2018–present
The 2017 season was the third and final year contested with the Chevrolet and Honda aero kits outfitted to the Dallara DW12 chassis. Beginning in 2018, the first season contested under the Johnson banner, chassis construction was deregulated, and teams no longer had to strictly run Dallara-made chassis. Among the chassis constructors were Panoz, Stohr Cars, Swift Engineering, and Eagle, with several teams such as Team Penske, Chip Ganassi Racing, and Andretti Autosport designing and building their own chassis. Starting with the 2018 season, all chassis had their own unique aero kits.

Transmission, gearbox, and clutch
For the transmission gearboxes, all IndyCar Series cars currently use an electronically-actuated AGS (Assisted Gearchange System) 6-speed semi-automatic sequential gearbox with an electro-pneumatically operated paddle-shift system and a pneumatic clutch with semi-automatic activation, supplied by Xtrac Limited since the 2008 season. All current IndyCar transmissions use pneumatic actuation for the shifting and clutch, so the clutch is therefore only needed for launching the car from a standstill, and the clutch isn't required for gear shifting. From 1996 to 2007, all IndyCar Series cars used a hand-shifted 6-speed sequential manual transmission with a shift lever, supplied also by Xtrac since 2000 season until 2007. The clutch of all IndyCar Series cars are carbon with steel housing 3-plate clutch operated by foot-pedal in 1996–2011 later hand-paddle steering wheel clutch in 2012–present and provided by AP Racing. Mechanical limited-slip differentials are also allowed and constant velocity joint tripod driveshafts are also used. All IndyCar Series car drivetrains are currently rear mid-engine with rear-wheel-drive layout.

Methanol
At its inception, the IRL used methanol racing fuel, which had been the de facto standard in American open-wheel racing since the 1964 Indianapolis 500 Eddie Sachs - Dave MacDonald crash. Methanol had long provided a safer alternative to gasoline. It had a higher flash point, was easily extinguishable with water, and burned invisible. With the IRL's introduction of night races in 1997, the burning of methanol fuel was visible for the first time, seen with a light blue haze. With this in mind, in an effort to make it more visible in case of fire during daylight hours, additional mixtures were placed in the fuel. As a safety feature, the methanol would burn with color.

Ethanol
In 2005, the driver Paul Dana brought the sponsorship of the Ethanol Promotion and Information Council (EPIC) to his IndyCar team. EPIC is a consortium of ethanol producers that advocate the increased use of ethanol. EPIC was anxious to address public concerns of that era that ethanol use led to engine damage and poor performance when used in road cars. As a marketing effort, it was believed that sponsoring an IndyCar could be used as a tool to promote education and awareness of ethanol use and to curb the spread of erroneous information.

Dana was killed in a crash in 2006, but the IRL had already begun a transition to ethanol fuel. For the 2006 season the fuel was a 90%/10% mixture of methanol and ethanol. Starting in 2007, the league advertised "100% Fuel Grade Ethanol," the first competitive series to utilize renewable fuel. The mixture was actually 98% ethanol and 2% gasoline, provided by Lifeline Foods of Saint Joseph, Missouri. The additives satisfy the U.S. government's demand that the alcohol is unfit for human consumption and add visible color in case of fire. However, 2010 São Paulo Indy 300, held in Brazil –outside of the U.S. regulations– utilized a full E100 mixture, the first instance in the sport.

To compensate for the loss of power due to the use of ethanol, the displacement was increased back to 3.5 liters. Since ethanol gets better fuel mileage than methanol, the fuel tanks in the car were decreased.

Compared to methanol, human contact with the current ICS fuel is much less harsh, and the fumes much less irritating. The fumes are often compared with the sweet smell of apple cider or apple cobbler. Unlike methanol, ethanol is not caustic and does not cause chemical burns when it comes in contact with the skin. It also is less polluting when spilled compared to methanol.

In May 2010, Sunoco became the official fuel of the series starting in mid-2010 with an immediate effect, running through 2018. Starting from 2012 season the Ethanol fuel blend rate has been reduced to 85% blend in a reference of road car relevance. Union 76 took over as series official fuel supplier beginning from 2019 season onwards but the E85 Ethanol still retained until at least 2020.

Fuel cell
The fuel cell for all current IndyCar Series cars are made of rubber and are covered with a Kevlar-fitted blanket for extra protection in side impacts. Since 2012 the capacity has been 18.5 US gallons (70 litres). Previous capacities were 22 US gallons (83 litres) in 2007–2011, 30 US gallons (114 litres) in 2004–2006, and 35 US gallons (132 litres) in 1997–2003.

Engine competition era (1996)
The initial 1996 IRL season, as well as the first two races of the 1996–97 season, featured engines with specifications leftover from the rival CART series competition. Those chassis/engine combinations were essentially under the same rules utilized by teams that participated in the 1995 Indianapolis 500, which was sanctioned by USAC. V-8 powerplants were allowed the typical 45 inHg (1.5 bar; 22.1 psi) of pressure boost. The Menard-Buick V6 engine used in 1996, however, was an updated powerplant from the 1995 version. In addition, the V-6 stock block engines (Buick-Menard) were allowed 55 inHg (1.9 bar; 27.0 psi) of boost at all races, instead of just at Indianapolis. During the CART era, V-6 stock blocks were only allowed 45 inHg (1.5 bar; 22.1 psi) at all races outside of Indy, which was a decided disadvantage and left the engine out of favor.

Ford-Cosworth reluctantly provided support to teams wishing to run their older-spec engines in the IRL, a major point of contention for CART management, to whom Ford-Cosworth was an official engine supplier. The Ilmor Mercedes V-8 engine, also a mainstay CART powerplant, was permitted, but the only time it was used as a one-off at the 1996 Indy 500 by Galles Racing.

Engine competition era (1997–2005)
Starting in 1997, IRL cars were powered by 4.0-litre V8, four-stroke piston, Otto cycle methanol-burning, production prototype-based, naturally-aspirated engines and electronic indirect multi-point port fuel injection, produced by Oldsmobile (under the Aurora label) and Nissan (badged as Infiniti). Per IRL rules, the engines sold for no more than $80,000, and were rev-limited to over 10,000 rpm and weighed up to 280 lb (127 kg) (excl. headers, clutch, ECU, spark box or filters). They produced around 700 hp (520 kW). These engines utilized 90° crankshafts, and while the engine blocks were to be production-based, they were not "stock blocks" like the Buick or Menard engines of the 1980s and 1990s. They were purpose-built racing engines.

The engine formula was changed with the 2000–2004 formula. The displacement was dropped down from 4.0 to 3.5 litres (244 to 214 cubic inches), and the requirement for the block to be production-based was dropped. The engines also switched to 180° crankshafts, and the rev limits were adjusted from time to time. This formula was used through 2003. In 2004, in the wake of several crashes including the fatal crash of Tony Renna and the severe crash of Kenny Bräck, the displacement was reduced to 3.0-liters using the existing engine blocks to curb top speeds (started from the 2004 Indianapolis 500).

Infiniti's engines, though reliable, were significantly down on power compared to the Auroras in 1997, leading many of the teams that had initially opted for the Infiniti to switch. By the end of the 1998 season, only a handful of low-budget teams were using the Infiniti. However, early in the 1999 season, Cheever Racing, a well-funded team, was brought on to develop the engine with team owner Eddie Cheever expanding the team to two cars and bringing on his brother Ross Cheever as a test driver. By 2000, the engine had improved markedly and Cheever captured the marque's first win at Pikes Peak International Raceway. However, despite the improved success, few teams made the switch to the Infiniti and the company left the series after the 2002 season to focus on powering the league's new Infiniti Pro Series (now Firestone Indy Lights).

As part of General Motors' discontinuance of the Oldsmobile name, the Olds engine was rebadged as the Chevrolet starting with the 2002 season. However, the effort could not compete with the Toyota and Honda programs starting in 2003. In August 2003, Chevrolet announced to the public its "Gen IV" motor, a rebadged Cosworth motor for competition. At the time, Cosworth was owned by Ford. On November 4, 2004, Chevrolet stated that it would be ending its IRL engine program effective with the end of the 2005 season, citing costs that exceeded value, according to then GM Racing Director Doug Duchardt, "The investment did not meet our objectives."

In 2003, Toyota came to the IRL from the rival CART series. Toyota won its first race in Miami, as well as the Indianapolis 500 and the series title. However, Toyota had just one podium in the last seven races of 2004, and only Penske Racing fielded competitive Toyota-powered cars in 2005. In November 2005, Toyota company officials announced the company's withdrawal from American open-wheel racing and the immediate discontinuation of its IRL program, coinciding with its entrance into NASCAR's Craftsman Truck Series in 2004, and its discontinuation of its IMSA program.

Honda also came to the IRL in 2003, and by 2005 was clearly the dominant engine manufacturer.

Single-manufacturer spec engine era (2006–2011)
After Chevrolet and Toyota elected to shut down their IRL involvement after 2005 season (Chevrolet temporarily hiatus from IndyCar Series for six years while Toyota USA elected to focus on NASCAR involvement), Honda became the only standard spec-engine manufacturer in the IndyCar Series starting in 2006 and continued in that capacity through 2011 as it was announced by Indy Racing League president & chief operating officer Brian Barnhart and Honda Performance Development president Robert Clarke on December 15, 2005. The Honda Indy V8 engine was partnered and co-developed by Ilmor, which is part owned by Roger Penske for tune-up, engine maintenance, arrangement and trackside support. The engine displacement was reverted back from 3.0 to 3.5 litres (183 to 214 cubic inches) beginning from 2007 season.

During that time, since the IndyCar Series had only one engine manufacturer, Honda focused on minimizing engine failure and minimizing costs instead of defeating rivals. As such, the engines were moderately de-tuned. The engines proved themselves to be quite durable — there had been no engine failures at Indy from 2006 to 2010, which also lowered the number of crashes. Most of the engines, including those used for the Indy 500, are used for multiple races and were intended to last 1,200  miles (1,931  kilometers) between rebuilds. The Honda engines were only available via lease arrangement from Honda, which, for the 2010 full season, cost $935,000 U.S. per season, per car.

IndyCar Series engines were rev-limited to 10,300 rpm + 200 rpm push-to-pass and produce approximately 650 + 40 hp push-to-pass. The valve train is a dual overhead camshaft configuration with four valves per cylinder. The fuel feed of Honda Indy V8 engine was an electronic indirect multipoint port fuel injection. The crankshaft is made of alloy steel, with five main bearing caps. The pistons are forged aluminum alloy, while the connecting rods are machined alloy steel. The electronic engine management system is supplied by Motorola, firing a CDI digital inductive ignition system. The engine lubrication is a dry-sump type, cooled by a single water pump.

In 2009, Honda froze the Indy V8 engine development for the 2009-2011 seasons due to Honda focusing on a new third-generation V6 turbo engine for the 2012 season.

Engine competition era (2012-present)
The current, third-generation IndyCar formula was introduced in 2012 including two new manufacturers, and marked the return of the IndyCar Series engine manufacturer competition war since the 2005 season. The engines are now fuel-efficient DOHC 2.2-liter twin-turbo V6 with four-stroke piston Otto cycle developing an estimated 550–750 hp depending on the level of boost used and no inter-cooling systems. They are limited to 12,000 rpm and weighed up to 248 lb (112 kg). Engines are currently supplied by Chevrolet and Honda. Since the 2012 season, McLaren has supplied its TAG-400i engine control unit. The current engine fuel injector delivery now combines direct and electronic indirect injection which produces roughly 300 bar (4,351 psi) of rail pressure. No fuel flow restriction exists in the IndyCar Series engine configuration. Chevrolet returned to the series in 2012 to provide all-new, Ilmor developed and engineered, V6 twin-turbocharged engines after six-year hiatus while Honda still remain committed to the series also to provide all-new V6 single-turbocharged engines in the same year. Lotus Cars provided an engine developed by Judd in 2012, but left the series in 2013 after lack of interest from teams in running the underdeveloped, uncompetitive, and unreliable Lotus engine. The push-to-pass overtake system was reintroduced during 2012 Honda Indy Toronto round and still being used currently that produced roughly 60 hp (45 kW) with a duration about 6–200 seconds of usage rechargeable (varies track shape). Porsche also expressed interest in joining the series as a third engine supplier in 2019. Ultimately Porsche backed out when IndyCar refused to allow them to field a hybrid powertrain. Coincidentally IndyCar announced its plans for a hybrid powertrain from 2023 onward one month later.

Further engine suppliers did end up joining in 2019. These included Ford (who had last competed in IndyCar via Cosworth in 2005), Dodge (which had never competed in IndyCar or even CART or USAC due to focusing on NASCAR and NHRA), Toyota (which had pulled support after 2005), Mercedes-Benz (a newcomer to the American open-wheel scene, but a dominant builder in Formula One competition), and Oldsmobile (which had been acquired by Johnson in 2004)

Chevrolet was the first engine manufacturer to utilize the twin-turbocharged configuration alongside Lotus in 2012 while Honda was utilized the single-turbocharger in 2012–2013. Honda ditched the single-turbocharged after 2013 in favor of twin-turbochargers from 2014 until the present.

Turbocharger
The turbochargers are reintroduced from the start of 2012 season. The turbo configuration is currently twin-turbocharged that mandated since 2014 and producing the turbo boost level pressure range restricted to 1.3–1.6 bar (19–23 psi) depending on track shape. American turbocharger company BorgWarner Inc. currently supplies exclusive turbocharger kits including wastegate for all IndyCar Series cars from 2014 season onwards using an EFR7163 model. Previously BorgWarner EFR9180 (single) was used exclusively by Honda-powered cars while BorgWarner EFR6758 (twin) were used exclusively by Chevrolet and Lotus (2012) powered cars.

The turbochargers of all IndyCar Series engines are incorporated by intercoolers.

Fourth generation (2023–)
The upcoming, fourth-generation IndyCar engine formula will be introduced for 2023 season with engine displacement will increase from 2.2 to 2.4 L (134 to 146 cu in) and also horsepower increase from 550–700 to 900 hp (410–522 to 671 kW) while the V6 twin-turbo engines will remain despite power and displacement increase. In addition, hybrid systems will also be introduced as relevance to hybrid road vehicles. The current third-generation IndyCar Series engines will retire after 2021.

The hybrid technology will consist of a multi-phase motor, inverter, and electric storage device that will create energy recovery from the car's braking system.

The addition of the hybrid technology to the traditional engine formula will provide some integral benefits for the competitors while enhancing the race action for the fans. In addition to allowing drivers to restart their cars from the cockpit, the system will increase the horsepower of the push-to-pass system and potentially improve the pace and overall time of races.

The addition of the hybrid powertrain will push the debut of the new engine formula from 2022 to 2023, realigning it with the arrival of the next-generation chassis as initially scheduled. The move will allow INDYCAR to continue working on other future innovations for the new package as well as extend the window of opportunity for an additional OEM (Original Equipment Manufacturer) to join Chevrolet, Ford, Dodge, Toyota, Honda, Mercedes-Benz, and Oldsmobile in 2023.

The new engine regulations will be in place for years - 2023 and beyond seasons - in a concerted effort to provide a clear vision and stability for the NTT IndyCar Series engine manufacturers and teams. It is a continuation of INDYCAR's initial five-year strategic competition plan that originated in 2016. According to RACER.com, INDYCAR accepted proposals from 10 companies for KERS vendors bidding candidates. Jay Frye stated: “We’ve had American companies, European companies; it’s been a multinational response, some came out of the blue, which has been good. We’ve learned about some new vendors when we asked for RFPs, and some have been from companies we’d expect to weigh in".

In addition to relevance to hybrid road vehicles some have noted that the new engine formula's timing comes as Formula One is introducing a development cost budget cap. Pundits have seen this as an opportunity to bring in a manufacturer from the F1 or even NASCAR to Indycar, as Formula One engine manufacturers having significantly more experience with hybrid powertrains in racing configurations than any of the existing engine suppliers besides Toyota. After failing to court Porsche following the 2019 season, Tim Johnson explicitly stated that the series intended to court Ferrari to bring another hybrid powertrain to the series. Ferrari boss Mattia Binotto later confirmed the talks and stated Ferrari was strongly considering bringing a powertrain to the series so as to retain employees they could no longer pay under the F1 Budget Cap. Ultimately however Ferrari elected not to participate in the series, with current rumors pointing to Johnson-owned Pontiac participating instead.

Spark plugs
Currently ACDelco (Chevrolet), Motorcraft (Ford), Mopar (Dodge), Bosch (Mercedes-Benz and Oldsmobile), Toyota Racing Development (Toyota), and NGK (Honda) providing spark plugs for all IndyCar Series cars since 2012. Previously NGK was an exclusive spark plugs supplier in 2006–2011 when Honda was the standard IndyCar Series engine supplier. Denso also was a sparkplugs supplier in 2003–2005 for Toyota-powered cars.

Racetracks
After the split from IndyCar World Series, the Indy Racing League began as a pure oval race series. Alongside the prestigious Indy 500, the 1-mile oval tracks of Phoenix and Loudon were added to the schedule. In addition, the Hulman family oversaw the planning for the construction of a new track at Walt Disney World in Florida. On the new Walt Disney World Speedway the first IRL race took place in January 1996.

After the series was established, ovals used mainly by NASCAR were raced on. These included the newly built racetracks in Las Vegas and Fort Worth as well as the existing speedways of Charlotte and Atlanta. After a series of major accidents at Charlotte and Atlanta (the Charlotte accident saw three fans lose their lives to flying debris) and a lack of spectator turnout, however, the ovals of Atlanta, Charlotte, and Las Vegas were removed from the calendar. For the 2001 season, the IRL also began to race on ovals that were being used by CART. The circuits of Homestead and Gateway changed from CART to the calendar of the IRL, with the race at Walt Disney World being dropped in favor of Homestead. In addition, the new 1.5-mile ovals of Kansas, Kentucky, and Chicagoland were added. These tracks were the backbone of the IRL until 2011. After Roger Penske sold his racetracks (Fontana, Michigan, and Nazareth) to the International Speedway Corporation, the IRL began racing at these tracks in the 2002 season. Nazareth Speedway only held three races before ISC closed the track in 2004. Michigan Speedway was raced until the 2007 season and the Auto Club Speedway, formerly California Speedway, until the 2015 season.

The first major change took place in the 2005 season. For the first time in the history of the IRL, races were held at road and street courses. A street course race in St. Petersburg had been added to the calendar. In addition, races at Sonoma and Watkins Glen, the two NASCAR road course circuits were added. In 2007, the Mid-Ohio Sports Car Course was added. After the Champ Car World Series was dissolved in 2008, some of their races were taken over by the IndyCar Series. These were the street races of Long Beach, Detroit, and Toronto, and starting in 2016, Road America. In addition, a road course race at Barber Motorsports Park in Birmingham and an oval race at Iowa Speedway were scheduled and held.

The second big change took place in the 2012 season. In 2011, the series returned for the first time since 2000 at the Las Vegas Motor Speedway. In the meantime, however, this circuit was rebuilt for NASCAR, increasing the banking of 12 degrees to progressive banking up to 20 degrees. This new configuration led to tight pack racing. To make matters worse, a $5 million bonus was offered if a driver from another series or racing discipline win the race, as it would be the last race for the current chassis, a record 34 cars entered this race (the Indy 500 field, by comparison, is capped at 33 cars). As a result of pack racing in combination with many cars and inexperienced drivers, a major crash occurred 13 laps in, injuring several drivers and killing the defending Indy 500 winner Dan Wheldon. This event led to massive media criticism of oval races for open-wheel vehicles. As a result, and also because of the gradual loss of spectators in the previous seasons, all oval races on 1.5-mile speedways, save for Texas Motor Speedway, were removed from the calendar. Only the oval races in Indianapolis, Milwaukee, Iowa, Texas, and Fontana remained for the next three seasons. Instead, more races were held in cities, including Houston, Baltimore, and São Paulo. In the following years, the calendar stabilized, with the return of races in Phoenix, Pocono, and Gateway, despite the races at Fontana, Pocono, Phoenix and Milwaukee being removed from the schedule after a short guest appearance due to insufficient crowd or bad promotion.

Since the 2012 season, the calendar consists of 1/3 of oval races, 1/3 of races on permanent natural road courses, and 1/3 of races on temporary street courses in larger cities. In 2019, an IndyCar race was held for the first time on a current Formula 1 racetrack, the "Indycar Classics" at the Circuit of the Americas in Austin, Texas.

The third big change took place when Johnson acquired IndyCar in 2018. All road course and street course races were removed from the schedule and moved to the revived Champ Car Series, which was now a division of IndyCar LLC. The Indianapolis 500, Texas, Pocono, and Gateway were retained, and races were added at Atlanta, Auto Club, Charlotte, Chicagoland, Dover, EuroSpeedway Lausitz, Homestead-Miami, Iowa, Kansas, Michigan, Milwaukee Mile, Nashville Superspeedway, Nazareth, New Hampshire, Pikes Peak, Phoenix, Richmond, Rockingham, and Twin Ring Motegi. Races at Daytona, Talladega, the new Walt Disney World Speedway, and Tokyo were briefly considered but quickly rejected due to Tim Johnson considering such races "high-speed suicide pacts".