Renault has brought an updated internal combustion engine to the race, which the team believes will deliver some minor improvements.
The engine upgrade will be a Spec C, however as it goes over the quote of what drivers are allowed to take per season without incurring a penalty, both drivers are expected to drop five positions following qualifying on Saturday.
"We will be using a new ICE on both cars today," read a team statement. "It's a spec C, with minor upgrades to reliability and performance. Introducing here will incur a 5 place penalty for both drivers for Sunday's race."
* includes ICE fitted at Spa
The Enstone squad has endured a tough season so far in 2019, as it is currently sixth in the constructors' championship, 43 points down on midfield leaders McLaren.
Bahrain International Circuit - Winter testing