After a sluggish start, Belgian rookie Vandoorne is now regularly competitive alongside his McLaren teammate Alonso, who is arguably one of the best F1 drivers ever.
"He's probably the best reference in Formula 1," Vandoorne agrees.
"I have a good relationship with him, even if there is a lot of competition, which is normal.
"We do not have a strong package this year, but it has been positive for me because I had the chance to get quite close to him."
Vandoorne insists that Alonso was not his "mentor".
"No," he told Brazil's Globo. "Of course we work together on the same team and in the same direction, but he does not stand next to me helping.
"We are very open and have normal conversations when we are out of the car. But he is not there to be my mentor.
"Maybe Lance needs this, I don't know."
Vandoorne has picked up 13 points to Alonso's 15 over the course of 2017.