The once-promising Belgian is not only struggling with the below-par McLaren-Honda package, but being consistently outshone by his teammate Fernando Alonso.
But he told Brazil’s Globo: “I don’t think you can compare us yet.
“The two cars are almost never on the track at the same time and under the same conditions. When one runs the other has problems.
“If you look at the results – the numbers – it’s true that Alonso is ahead, but we’ll see what it looks like when there are not so many interfering variables,” Vandoorne, 25, added.
And so the 2015 GP2 champion said he, and also McLaren, still has faith in his ability.
“I have no doubts,” said Vandoorne, “and once I have a fast car it will show.
“The timing of our project requires us to work together to overcome the difficulties, so this is the priority.”
When asked specifically about McLaren’s faith in him, Vandoorne answered: “They know my ability, what I demonstrated in the past, and that I am trying everything to help the team out of this difficult situation.
“I go to the factory a lot, I encourage the group, and they know I’m giving 100 per cent – my maximum – and that’s all I can do.”
Finally, McLaren boss Eric Boullier denied rumours the gap between Alonso and Vandoorne is because of inequality in the equipment supplied to the drivers.
“It is 100pc false,” the Frenchman told the RTBF broadcaster.
“Many people forget that it takes time for young drivers who arrive in formula one.
“Even Verstappen had to acclimatise at Toro Rosso, and it was the same for Ricciardo and many others,” said Boullier.
“What is more difficult for Stoffel is that he has one of the best drivers on the grid at his side. But when he really has the car he needs, as at the beginning of the weekend here in Austria, he is at most a tenth behind,” he added.