Red Bull boss Christian Horner says that the team's choice of ExxonMobil's oil and fuel for its Renault-provided engine is actually proving an advantage.
Horner was responding to comments made by Toto Wolff earlier this week. The Mercedes team principal suggested that his rivals had made a "strategic mistake" with the decision.
Red Bull are the only engine customer team on the grid this year not to choose the same oil and fuel supplier as their manufacturer's works team.
Renault uses BP/Castrol for its oil and fuel requirements, as does McLaren. All teams with Mercedes engines are serviced by Petronas. Similarly, Ferrari stipulates that Haas and Sauber should use Shell.
Red Bull and the Renault works team both used Total products in 2016. However, they went with different solutions the following season.
"I see Toto has been making a load of comments on this," Horner told Sky Sports News on Friday, during the final day of pre-season testing at the Circuit de Barcelona-Catalunya.
"We see it as an advantage," he insisted. "We have a great relationship with Exxon and have done for the last 12 months.
"Their products won three Grands Prix last year," Horner pointed out. "They are producing some great products and we see it as a technical advantage."
Wolff had argued that each power unit package was optimised for use with a particular fuel and oil. He added that any savings from going with an alternate supplier would be swallowed up by the costs of running extra dyno testing.
Horner agreed that choosing a different supplier might not save money. However, he was confident that it was still worth it in this case.
"Obviously there are additional burdens involved in that as it's a different supplier than what the works team have," he concurred. "Iit just means they've got to run more engines on the dynos, which we have to cover the cost for.
"But we wouldn't be using it if we didn't see it as a technical advantage. They are a great company, great to respond, very quick and we see it as an advantage."
Although McLaren currently uses BP fuel and oil, it will change to Petrobas in 2019 as part of a sponsorship deal with the Brazilian company.