As Force India's technical director Andrew Green said: "We've got to see where they [the tyres] go when you start taking the downforce off the auto, which is something we've not really experimented with yet".
"But Vettel won with a clear victory".
Last year, Mercedes finished almost 300 points ahead of Red Bull in the constructors' championship, winning 19 of 21 races as Rosberg pipped Hamilton to the title before dramatically announcing his retirement from Formula One.
It used to be a case of guessing the winning margin for Mercedes in the constructors' championship, and a toss-up between which of its two drivers would win the Formula One title.
Vettel is doing better, by comparison, with three wins and three second places, and makes a plausible argument when he says Ferrari could have won every race this year had everything gone to plan. "First of all, they deserved the win - they had the quickest vehicle out there so as a team result, the one and two is good and congratulations from our side. Maybe they won't, but I'd like to think so".
Speaking about Ferrari, Isola said: "I am not a vehicle dynamic expert but I think they have designed a auto that is very good with the setup". "Because the underdog is the one that people want to see win".
Getting tyres into the right operating window is nothing new in Formula 1, but the situation this year has been made especially hard because of two factors.
"Our target would be it's the worst race of the season, hopefully, and an outlier like we had in Singapore", he said.
With new regulations created to make cars wider, heavier and faster this year, Ferrari seems to have worked wonders in the factory while Mercedes appears to be going backward.
The season continues next weekend in Canada.
"We need to understand it because Ferrari is able to understand and race the auto in these conditions".
Three-time world champion Hamilton suffered a torrid time in Monaco last weekend.
"For some reason Ferrari always seems to have both axles working, while for us they're not really coming together, they're never at the same time in the correct window and they're doing a better job at that, at the moment".
"Trust me the guys are pushing hard to fully understand as we can't get into this position again as one more race like this and we'll be much further behind". "Twenty-five points is a long way away, it was hard to get just six points, but bit by bit, we'll try and chip away".