Red Bull motorsports consultant Dr Helmut Marko says that the team's new tie-up with Honda should make them "massive" in Japan.
Red Bull is currently seeing out the final weeks of its engine deal with Renault before switching to Honda next season. It's junior Toro Rosso squad has already blazed the trail for them this season.
Marko was commenting after Pierre Gasly and Brendon Hartley both received heroes' welcomes from Japanese fans when both Toro Rossos succeeded in qualifying in the top ten at Suzuka last weekend.
"We got so much welcome in Japan," Marko told Motorsport.com. "Can you imagine if we start winning? Being a frontrunner, I think it will be massive.
"We are really looking positive for next year with a different engine. We saw what they can do in qualifying here."
Red Bull team principal Christian Horner also commented that Honda's progress on the power unit front was looking very positive.
"It's great to see them making real strides. We're very excited about the progress they're making, and obviously hopeful as we head into 2019."
However the race itself did not go so well for Toro Rosso, with Gasly dropping to 11th and Hartley to 13th by the finish. It meant they came away from Honda's prestigious home race without any points.
"The result was disappointing, given our excellent showing in qualifying," admitted Honda F1 technical director Toyoharu Tanabe.
"However, the frustration we all feel at the lack of points will be turned into motivation as we carry on working for the final four races."
Gasly - who will move from Toro Rosso to Red Bull next year - remains confident that the manufacturer is on the right track.
"I think with the improvements of Honda, the steps they are making at the moment, we could be in a really good position," he said.
"We'll see in six months time. A lot of things can happen. I don't want to think too much about it now."
The Frenchman suggested that Toro Rosso might be being held back by the sudden departure of technical boss James Key, who is set to join McLaren after a spell of gardening leave.
"You could say that if a team loses its technical director, that will always have an impact on performance," Gasly is quoted by Brazilian free-to-air television network Globo this week.
"We didn't really have any upgrades on the car since Melbourne," he added. "Or there was a very small one in Monaco and the one in Austria didn't work."
The 22-year-old is hoping that Honda will be able to get on top with teething problems on its latest engine upgrade - even if that means incurring grid penalties in the final races of 2018.
"We know that if we introduce more engines we will have penalties. But certainly with the new specifications, we will have a better chance of fighting for better things in the last races."
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