The Pole, whose Formula One career was cut short after a rallying accident almost claimed his life in 2011, has made just one circuit racing appearance since leaving F1. That was in the 12 Hours of Mugello earlier this year.
Kubica will drive alongside Christophe Hamon for Duqueine Engineering at Spa and completed a shakedown of the car earlier this week.
"I quickly felt at ease at the wheel of the R.S. 01, and even on a twisty track like Ales its qualities were immediately evident, especially the stopping power granted by the carbon discs," Kubica said. "I was impressed by how late into the corner you can brake and by the absence of body roll, even when you push to make the most of the available grip."
"I look forward to driving it at Spa, where all the downforce the car can generate will also come into play."
Kubica has competed in rallying since his F1 departure, winning the WRC2 title in 2014 before moving into the World Rally Championship where he competed from the end of 2014 until earlier this year.
Bahrain International Circuit - Winter testing
Would you like to stay up to date with the latest Lewis Hamilton and Formula 1 news from GPtoday? Activate free push notifications and be the first to know!