Deletraz has been team-mates with ex-Formula 1 driver Kubica since 2021, when he moved full-time into endurance racing after making select GT World Challenge Europe outings and finishing fourth in a Le Mans one-off with Rebellion in 2020.
Together, the Swiss and the 2008 Canadian Grand Prix winner claimed the 2021 European Le Mans Series crown with WRT and were only denied victory at Le Mans by a freak failure on the final lap.
They continued with Prema for the 2022 WEC, finishing second at Le Mans, and upon reverting back to WRT repeated the result earlier this month after losing out to Polish squad Inter Europol Competition by just 21 seconds.
Speaking to Autosport, two-time European Le Mans Series champion Deletraz said his partnership with Kubica had been instrumental in helping him reach the point of earning a first manufacturer deal as an endurance extra for Acura squad Wayne Taylor Racing with Andretti Autosport in the IMSA SportsCar Championship.
"I’ve evolved a lot because meeting Robert in ’21, yes he’s a friend, but he taught me so much," said Deletraz, who currently leads the WEC P2 standings with Kubica and Rui Andrade.
"He’s I think a legend of the sport. Technically speaking, there is no drivers I have met that are as strong as him.
"Being by his side, seeing how he works, understanding a car and how to make it fast - in the last two and a half years I went from probably knowing 20 per cent to maybe 90 per cent of the game.
"Technically speaking he’s been an amazing teacher and I wouldn’t be here without him."
Deletraz believes a key element to their successful partnership is a shared deep-running passion for motorsport, with Kubica having competed in several disciplines of motorsport including rallying.
"I think that’s the key thing here is we really became friends and share a lot of values, not only on track," said Deletraz, whose father Jean-Denis made three F1 starts for Larrousse and Pacific in 1994-95.
"I met Robert in ’21 the first seat-fit, we straight away got along. He has a passion for motorsport which is incredible, he is the most passionate person ever about motorsport in general, every single category.
"And I also can share that, I grew up in motorsport with my dad and I love motorsport, I’m happy to be able to live my passion. And we have the same desire to win and perfections of every detail. And I like to work hard with people, with a team.
"If you have this relationship, you don’t want to change. You want to keep it as long as possible and it’s fantastic we’ve been able to do it three years in a row."
Deletraz has become one of the most in-demand LMP2 drivers of recent seasons, having helped John Farano to secure the IMSA P2 crown last year with two wins - missing only a single race at Mid-Ohio due to a clash with the Imola ELMS round.
He scooped a second ELMS title with Ferdinand Habsburg last season and currently leads this year's standings after winning the Barcelona opener for TF Sport, despite being entered in the pro-am subdivision.
After four winless seasons in Formula 2 in which he finished runner-up six times, Deletraz believes he's now back to performing at his best.
"I had a tough time in Formula 2 for many reasons, not the right place in the right moment, there’s also a lot of politics in the sport," he said.
"And Formula 2 the last three years were tough. Before that in Formula Renault and World Series [Formula V8 3.5], I used to win every weekend, as well I got my [F1] superlicense and I think I’m back to this.
"Back to the times where every weekend I was coming to a racetrack I could win races and I think that’s what drives me."
