The team made strong progress last year and totalled a healthy 48 points, but Vasseur claims they can only see growth if they look at data from the top teams. And that won't come as foreign information to Ferrari legend Kimi Raikkonen, who has moved back to Sauber.
"We also made progress on the circuit due to the performance of McLaren and Williams, who had more problems than we expected, so I prefer to look at the percentage gap with the top teams, which is the best way for me to see how we perform. They have a lot of resources at their disposal, so if we can ensure that the gap remains the same, we will perform better," Vasseur told Gpupdate.net.
Vasseur confirms he is pleased with the improvements over the past 12 months but holds fire on repeating the same feats in 2019. He warns his team that it'll be harder to make the same improvements because of how well they did in 2018.
"I do not want to be negative because that's not the atmosphere within the team, but it's a lot easier to make up for ground when you're four seconds slower than when you have to fight for a few tenths," Vasseur added.