The success is likely to continue for McLaren as the Losail circuit in Qatar is predominantly high-speed which suits their car characteristics.
While Stella is “encouraged” by McLaren’s development for next year, the Italian was quick to mention Mercedes.
He said after Suzuka: “Let's not forget that Mercedes, I think they realised what they need to work on. And I suspect they're going to jump back quite strongly.
“There are no factual elements at this stage to say this is the pecking order we'll see next year. I think things can evolve.”
Given McLaren’s unprecedented mid-season jump up the pecking order, Stella conceded they are currently “slightly ahead” of where they expected.
“At the moment, we are encouraged by the development we see on next year's car,” he added.
“Looking at the season, if we really want to check against this best expectation, I think we are slightly ahead of where we would have expected to be even in the most optimistic prediction.
“But, at the same time, I guess it's the same for everyone because right now some concepts are starting to be quite clear across the paddock.
“We don't know whether we are developing faster than other teams. And above all, we don't know whether we are developing faster than Red Bull.