Red Bull have moved to defuse a toxic row between their junior team Toro Rosso and engine supplier Renault.
Red Bull motorsport boss Helmut Marko said: “There has never been any question we have not been treated fairly by our engine suppliers.”
His statement followed a public row between him and Renault F1 boss Cyril Abiteboul at the Brazilian Grand Prix.
Toro Rosso had implied Renault might be sabotaging their engines, which have suffered a series of failures.
Marko said in a statement: “Over the last 10 years, many successful, we have been through every emotion with our current engine supplier. As usual at the end of another long season, emotions are running high but it is a valued relationship and will remain so.”
Toro Rosso’s statement had followed Abiteboul saying the failures may be caused by Toro Rosso’s car.
Abiteboul told the motorsport network websites on Friday after engine problems for both Toro Rosso drivers Pierre Gasly and Brendon Hartley: “We do have a little bit of concern about the way that our engine is operated in the Toro Rosso car”, adding that there are “never coincidencies” in F1.
A statement by Toro Rosso said that the problems were “not associated with how the team is operating or how the PU (engine) is integrated in the chassis”.
It added: “One of the primary reasons for the issues we are seeing is the lack of new power unit parts available.
“In Toro Rosso’s case, the team is constantly having to change parts from one PU to another during the weekend and, on many occasions, is forced to run old specification assemblies.”
Toro Rosso went on to point out that they are fighting with Renault for sixth place in the constructors’ championship, adding: “The situation may not be a coincidence, but it is certainly not due to STR’s car.”
After the statement, Abiteboul stormed over to Red Bull and had a row with Marko before the final practice session at Interlagos on Saturday morning.
The two then met with other Renault bosses after the session to discuss the issue.
Abiteboul refused to comment on reports that Renault was considering ending its contract with Toro Rosso and leaving the team without engines for the final race of the season in Abu Dhabi in two weeks’ time.
The situation is playing out against the wider backdrop of the difficult relationship between Red Bull and Renault.
Renault, who won four consecutive championship doubles with Red Bull from 2010-13, have been angered by consistent public criticisms by Red Bull since the start of the turbo hybrid engine era in F1 in 2014.
Toro Rosso are switching to Honda engines in 2018, and Renault have told Red Bull they do not want to supply them beyond the end of next season.
However, Renault have a contract with F1 which obliges them to supply an engine to Red Bull if asked to do so, which effectively leaves Red Bull with a choice of Renault or Honda engines for the 2019 season.