Max Verstappen has been warned by Helmut Marko that reliability could still scupper his chances of a successful title defence this season.
The Dutchman has found some brilliant form this season as he looks to build on his maiden Formula 1 title from last year. He has won six of nine races so far, including five of the last six as Red Bull stamped their authority on both championships.
It was Ferrari who got the faster start at the beginning of the campaign, with Charles Leclerc winning two of the first three races. Verstappen has overcome the reliability issues he suffered with his car in those races to open up a 46-point gap at the top of the drivers' standings.
Red Bull advisor Marko knows, however, that mechanical problems can still strike at any time to derail a driver's season. The gearbox problem suffered by Sergio Perez at the Canadian Grand Prix was a reminder to his team-mate that his position at the top of the standings is far from a comfortable one.
"The main thing is you have to finish and avoid those reliability things," the Austrian told Autosport, referencing the DNFs suffered by Verstappen in Bahrain and Australia due to issues with the fuel line in his RB18. "We also had a sprint race, which helped us a lot to get more points.
"We have an unbelievable run now, normally in the first half of the season we were always catching up and now are dominating. You have to say that if you win seven races out of the first nine, that is domination.
"Reliability is always a concern if you have a car that is so much on the limit. You see that at Ferrari. The only ones who don't have a technical DNF yet is Mercedes, but they had to lift during some races because of overheating problems.
"You must, of course, not forget that these are completely new and heavier cars. You have almost no test time and immediately go to the limit. That's where the outages come in. We're relatively okay, well, on second thought, we're not okay at all! Four outages so far is just too much, but we're working on it."
