Renault Formula 1 technical director Nick Chester says is "a bit surprised" by the engine gains Ferrari has made through the 2018 season, but doubts it ♍is related to the way in which the team is running a blown rear wing.

After years of Mercedes dominance in the power unit stakes, Ferrari has emerged as the strongest engine supplier th🌱is season, with Mercedes team boss Toto Wolff estimating the t🌱ime deficit in a straight line at Hockenheim two weeks ago to be worth half a second.

Ferrari's latest engine update arrived for customer teams Haas and Sauber at the last race in Hungary ahead of the works team gain🅠ing the new parts at the next race in Belgium, giving the team another boost in its bid for both championships.

Asked by mahbx.com in Hungary if he was surprised by Ferrari's engine gains, Renault's Chester said: "They definitely made a big step Canada-time. I'd say yeah, we are a ൲bit surprised𝄹.

"They've got a sဣtrong engine anyway, but it's really quite sไtrong now. The performance is right up there."

One area of development earlier this year was the blown rear wing, but Chester does not thinkဣ Ferrari's recent gains have been down to advancements in that𒅌 area.

"Not that we'🍰re aware of. But it's always hard to know what another team is doing," Chester said.

"It just seems to be more power unit output. Their straight line speeds are very strong while running a sens꧙ible rear wing on the car. So they do seem to just have good power꧋."

Ferrari's power unit was investigated by the FIA in Monaco to ensure it was legal after concerns were raised by Mercedes over the Baku weekend, with the team being cꦦleared of any wrong-doing.

Further questions have been asked in the meantime, but FIA race director Charlie Whiting said at Hockenheim that the F🧸IA remained "satisfied" 𒐪with Ferrari's power unit.