Why iRacing’s IndyCar and NASCAR games will share physics but not graphics

It’s set to be a big year for iRacing Studios. iRacing’s publishing arm has taken ownership of both the NASCAR and IndyCar video game licenses and will likely release both titles in the following 12 months.

NASCAR 25 is hitting PlayStation 5 and Xbox Series X|S on the 14th of October, while its official IndyCar game is scheduled for the second half of 2026. 

In a surprising decision, however, iRacing has opted to use different graphics engines for each game, with the IndyCar project running on the Orontes Engine (as used in the company’s futuristic off-roader, ExoCross), while NASCAR 25 employs Unreal Engine tech.

But why has iRacing opted for this approach?

A different method

“I don’t think it’s a horrible decision to try different paths with the two studios to see what works best,” stated Executive Vice President and Executive Producer of iRacing, Steve Myers, to Traxion.

“Certainly, the Orontes Engine doesn’t have the full feature set that a full Unreal Engine would have. And a lot of the stuff that Rich [Rich Garcia, NASCAR 25 Game Director] is doing in that game is benefiting from Unreal technology, so I think for that game that made the most sense to go with it.” Myers explains. 

Perhaps most crucially of all, Myers lauds the work of Orontes Games, and their proprietary engine that powered ExoCross and the next year’s IndyCar title: “The Orontes team… they have an absolutely gorgeous graphics engine,” he enthuses.

“As a business, having a different approach with the IndyCar game and using our own code base, and [having] the graphics engine that we can develop, and [that] we can improve upon any way we want, allows us a different flexibility there,” he expands, possibly hinting that the decision was taken partly as a technical exercise to expand the company’s knowledge base.

“I think it’s a safe approach of trying two different paths, and in truth, I think we can learn things from developing both of those products to help us on the iRacing side and what we’re doing with redoing our graphics engines there,” he claims, suggesting that iRacing itself can benefit from improved visuals in future thanks to the multi-engine approach.

Physics

But what about physics?

“The beauty of what we’re doing as a business and building up these other properties and these other code bases is that we can leverage work that we’ve done in other studios,” begins Myers.. 

“So like for instance, the IndyCar game, the physics engine is the same physics engine in the NASCAR game,” he proffers.

“We’re going to have a unified ‘simcade’ physics model across all of our products. So there might be slight differences in features between NASCAR and IndyCar because of the way that Unreal works …but the driving will be the same. 

“So the feel that you’re going to have driving a NASCAR in 25 is going to be the same feeling you’re going to have driving in the IndyCar game,” Myers continues.

“We can build a team now that’s working on that physics engine, and that’s their job, and now they’re servicing multiple games and we can really perfect that engine for the purpose it serves.”

Myers seems to suggest that iRacing’s plan to use a singular physics base for iRacing Studios titles, with different game engines offering the business flexibility in future.

iRaicng benefits

Another key aspect of having multiple racing titles under the iRacing Studios banner is its massive repository of content.

“Every track that’s going to be in NASCAR 25 was updated in iRacing,” Myers begins. 

“If we have the track [in iRacing], it’s going to get a refresh. So everyone on iRacing benefits from the NASCAR 25 project already because every track in iRacing got updated for free,” he states, explaining how every track used in the 2025 NASCAR Cup Series will be playable in NASCAR 25 thanks to iRacing (barring the Autódromo Hermanos Rodríguez, which was only recently released to the sim).

Although NASCAR Cup cars and IndyCars drive very differently in the real world, using an all-in-one physics solution for both games makes sense in terms of economies of scale, as does utilising iRacing’s vast array of licensed cars and tracks.

While NASCAR 25’s Unreal Engine is a proven entity in the world of video games, the Orontes Engine perhaps faces a tougher task of delivering a top-tier experience, a goal Myers and iRacing believe it can achieve.