After a tumultuous semi-works relationship came to a head last year, the former world champion team agreed a one-year customer deal with Renault for 2016 involving the re-branding of the power units as Tag-Heuer.
In the meantime, the French carmaker bought Lotus and is back at full works status this year, with Red Bull officials saying that renewed focus has resulted in a definite step forward regarding the quality of the engine.
Nonetheless, Red Bull are waiting for a further performance step from Renault - expected in Canada next month - before deciding if they want to extend the deal into 2017.
"Before deciding on the future with Renault, we await their developments," Dr Helmut Marko, a leading Red Bull official, told Italy's La Gazzetta dello Sport.
"But for the moment we are very satisfied. It is a completely different situation than in 2015," he added.
The Canadian Grand Prix will take place on June 12.