iRacing runs over 30 official series across four racing disciplines, each restricted to specific license classes from Rookie through Class A. The best series for your level depends on your license class, preferred discipline, and whether you own the required cars and tracks. Most Rookie series use free content, while higher-class series require purchased vehicles and circuits.
Choosing the right series is one of the most impactful decisions you make in iRacing. Entering a series where you own all the content and match the license requirement means you can race every week without buying anything new. Entering a series where you are missing tracks or cars forces you to skip weeks or make unplanned purchases. This guide maps every major official series to its license class, content requirements, and typical participation level so you can plan your racing season effectively.
Rookie Series: Your First Races
Rookie series use only base content included with your subscription, so every new member can race immediately without any additional purchases. The Global Mazda MX-5 Cup is the most popular Rookie road series and runs 12-minute fixed-setup races every hour. The car is forgiving, the races are short, and the fields are always full. This is where most iRacing members learn the fundamentals of online racing.
The Formula Vee series offers a single-seater alternative for Rookies who prefer open-wheel racing. The car is slower than the MX-5 but teaches different skills—trail braking, weight transfer management, and open-wheel racecraft. The Vee races are also 12 minutes with fixed setups and run on the same schedule as the MX-5.
On the oval side, the Street Stock series and Legends Cup provide Rookie-level stock car and short-track racing. Both use free content exclusively and run on Charlotte Motor Speedway, USA International, and Lanier National Speedway. The Street Stock races are 15 minutes and feature close pack racing that teaches drafting and side-by-side skills.
Class D Series: Expanding Your Horizons
Class D introduces paid content for the first time. The Ferrari Challenge series races the Ferrari 488 GT3 Evo around popular road circuits in 15-minute fixed-setup sprints. This series is one of the most popular on the platform because the Ferrari is a relatively forgiving GT3 car that teaches advanced car control. The entry cost is one car purchase ($11.95) plus whatever tracks you do not already own.
The Porsche Cayman GT4 Clubsport series provides a stepping stone between the MX-5 and full GT3 machinery. The GT4 car is slower than a GT3 but faster than the MX-5, and the series visits a mix of free and paid tracks. The BMW M4 GT4 runs in a parallel series with identical format and similar participation levels.
For oval racers, the ARCA Menards Series in Class D represents a significant step up from Rookie Street Stocks. The ARCA car is faster, the races are longer at 20 minutes, and the competition is noticeably tougher. The series primarily races on intermediate ovals and superspeedways, and the pack racing dynamics are more complex than anything in the Rookie class.
Class C Series: The Competitive Core
Class C is where iRacing’s competitive depth really opens up. The GT3 Sprint series is the most popular road series on the platform, running 20-minute fixed-setup races with any GT3 car. The series visits a rotation of top-tier circuits and consistently fills multiple splits every hour. If you enjoy GT racing, this is the series that justifies the cost of reaching Class C.
The Porsche 911 Cup series races a spec Porsche with no traction control or ABS in 20-minute fixed races. This series is considered one of the most challenging in iRacing because the car demands precise throttle control and rewards smooth driving. The Cup car has a passionate following and the series consistently delivers clean, competitive racing.
NASCAR Trucks in Class C offer 40-minute oval races at superspeedways and intermediate tracks. The truck races are longer than the ARCA events and feature green-flag pit stops that add strategic depth. The series is popular among oval-focused drivers and serves as the primary feeder series for the higher-level NASCAR competition.
Class B and A Series: The Top Level
Class B unlocks the IMSA Michelin Pilot Challenge, which features multi-class GT4 and TCR racing in 40-minute events with open setups. This series demands awareness of faster and slower class traffic, making it a unique challenge that no other series on the platform replicates. The races are long enough to require pit strategy and tire management.
The NASCAR Xfinity Series in Class B runs 60-minute races at the same tracks as the Cup Series but with slightly slower cars. The Xfinity races are considered more accessible than Cup events while still offering the full oval racing experience including drafting, pit strategy, and pack racing at superspeedways.
Class A features the NASCAR Cup Series, which runs 100-lap or timed races at every major oval on the schedule. Cup races are the pinnacle of iRacing oval competition and attract the most skilled oval drivers on the platform. The races are long, the competition is fierce, and the strategy is complex.
The iRacing Endurance series and special events like the Daytona 24 and Spa 24 also require Class A or B licenses. These team events run for 6 to 24 hours and represent the most prestigious races on the platform. The preparation required for these events—setup development, stint planning, team coordination—makes them the sim racing equivalent of real-world endurance racing.
Series by Discipline and License Class
| Discipline | License | Series Name | Car | Race Length | Free Content? |
|---|---|---|---|---|---|
| Road | Rookie | Global Mazda MX-5 Cup | Mazda MX-5 | 12 min | Yes |
| Road | Rookie | Formula Vee | Formula Vee | 12 min | Yes |
| Road | D | Ferrari Challenge | Ferrari 488 Evo | 15 min | No ($12) |
| Road | D | GT4 Fixed | Any GT4 | 15 min | No ($12) |
| Road | C | GT3 Sprint Fixed | Any GT3 | 20 min | No ($12+) |
| Road | C | Porsche Cup | Porsche 911 Cup | 20 min | No ($12) |
| Road | B | IMSA Pilot Challenge | GT4 / TCR | 40 min | No ($12+) |
| Oval | Rookie | Street Stock | Street Stock | 15 min | Yes |
| Oval | D | ARCA Menards | ARCA car | 20 min | No ($12) |
| Oval | C | NASCAR Trucks | Silverado | 40 min | No ($12) |
| Oval | B | NASCAR Xfinity | Mustang / Camaro | 60 min | No ($12) |
| Oval | A | NASCAR Cup | Mustang / Camaro | 100 laps | No ($12) |
How to Choose the Right Series for You
Start by checking which series you can enter with your current license class and existing content. The iRacing UI shows your eligibility for every series, but manually checking the track schedule before the season starts saves you from entering a series where you are missing half the tracks. A series where you own 10 of 12 tracks is a good investment; a series where you own 4 of 12 is not.
Consider participation levels when choosing between similar series. The GT3 Sprint Fixed series fills multiple splits every hour, while a niche series like the Lotus 49 might only run one or two sessions per day. Higher participation means better matchmaking through the iRating split system, which produces closer and more competitive racing. Check the iRacing forums or series-specific Discords to gauge community size before committing.
Match your series choice to your available time. If you can only race 30 minutes at a time, the 20-minute GT3 Sprint or Porsche Cup series fit your schedule. If you have two-hour blocks available, the IMSA or endurance series offer deeper racing experiences. Choosing a series that matches your time availability prevents you from missing races and losing participation credits.
Frequently Asked Questions
What is the most popular series in iRacing?
The GT3 Sprint Fixed series is the most popular road series, consistently filling 3 to 5 splits per hour. On the oval side, the NASCAR Cup Series draws the largest fields. Both series use the most popular car classes on the platform.
Can I race any series with a Rookie license?
No. You can only enter series that match or are below your current license class. Rookie series use only base content, while D-class and above require specific cars and tracks. Your license class in each discipline determines your access.
How do I find out which tracks a series uses?
Each series publishes a 12-week schedule before each season begins. You can view it in the iRacing UI under the series details, or check the iRacing forums where schedules are posted weeks in advance with track names and configurations.
What happens if I miss a week in a series?
Nothing negative. You simply do not earn participation credits for that week. To earn the maximum $4.00 per season in participation credits, you need to race at least 8 of the 12 weeks. Missing one or two weeks still qualifies you for partial credits.
Are there free series above Rookie class?
Yes. Several Class D series use a mix of free content, and some weeks in higher-class series feature free tracks. However, most series above Rookie require at least one car purchase ($11.95) to enter.
Related Articles
- iRacing Series and Progression: A Complete Guide — understand the license system that gates series access
- iRacing Safety Rating: How It Works and How to Improve Fast — the clean-driving metric that determines your promotions
- iRacing Track Buying Guide: Which Circuits to Buy First — maximize value from track purchases across multiple series
- iRacing Cost Breakdown: Subscription, Cars, and Tracks in 2026 — budget planning for your racing season
- Best Sim Racing Games 2026 — how iRacing compares to other simulators
