As its name suggests, iRacing is all about the… well, racing. It sounds obvious for a sim racing platform, but other contemporaries, such as Assetto Corsa, are more about being a driving sandbox. iRacing, on the other hand, puts competitive online racing to the forefront. These ranked battles and special events are its core competence - the main reason to become a member. It’s not hard to find a busy grid with highly ranked drivers. Which is remarkable, really, considering the breadth of content on offer. NASCAR, dirt ovals, off-road, rallycross, Formula 1 cars, electric concept vehicles and GT3s. It covers the full motorsport spectrum. However, some series see more action than others, and knowing the most popular may help if you’re looking for the largest grids or most competitive rivals. Here are the top ten most-raced, according to iracingdata.com, with stats based on Season 4 2025.