When iRacing’s 2025 Season 4 build dropped, the biggest headlines focused on flashy new cars like the Aston Martin Vantage GT3 EVO and Dallara IL-15. But tucked into the release notes was a change that could reshape the way superspeedway racing feels in the sim: a major overhaul of the Gen4 NASCAR drafting model.
It doesn’t look dramatic in screenshots, but on track? It’s a different world.
What’s New Under the Hood
iRacing’s release notes describe the update simply as “extensive adjustments to drafting parameters for the NASCAR Gen4 car.” That’s understated. What drivers are finding is a much more nuanced aerodynamic model:
- Sidedraft is alive and well. Pull alongside another car’s rear quarter panel and you’ll feel it — your car drags theirs back while gaining momentum yourself. It’s no longer just a visual trick; it works like it did in the real Gen4 era.
- The air bubble matters. There’s now a clearer sense of “clean air” vs. “dirty air.” Get out of line or lose the pack, and the hole in the air your car punches won’t do you any favors.
- Dynamic packs. Gone are the days of stagnant two- and three-lane trains. The new drafting model encourages fluid movement, side-by-side shuffling, and actual passing opportunities.
How It Feels to Drive
Drivers are reporting a very different pack-racing experience. Some key takeaways:
- Lose the draft, pay the price. Falling out of line now means it’s much harder to claw back to the pack.
- Battling for air matters. Positioning on the track — not just raw speed — determines whether you move forward or get freight-trained.
- Closer to real life? Opinions differ. Some say the sidedraft feels a touch too strong compared to the real-world Gen4 cars. Others think it finally nails the balance between speed and strategy.
One thing is certain: you’ll need to relearn the art of pack racing. No more “easy ride in line” until the last lap — this update forces you to fight for clean air and defend your spot.
Why It Matters
The Gen4 car is a fan favorite in iRacing, serving as a nostalgic callback to an era of NASCAR that many sim racers grew up watching. Updating its drafting model does more than improve immersion — it keeps the car relevant for serious superspeedway racing and league events.
The new model also borrows from iRacing’s work on the Next Gen Cup car, where airflow, aero wake, and sidedraft play a huge role. Bringing that same tech to the Gen4 ensures consistency across the sim’s stock car lineup.
The Gen4 NASCAR drafting update isn’t just a tweak — it’s a fundamental change to how these races play out. Packs are livelier, strategy is deeper, and every move on track carries more risk and reward.
It may frustrate drivers who preferred the more forgiving old model, but for fans of high-stakes superspeedway action, this is as close as iRacing has ever come to capturing the chaotic beauty of Gen4 pack racing.
