Vettel to race yet another chassis in Singapore
The reigning world champion has struggled from the very first laps of the radically new turbo V6 era, initially with the chassis he affectionately called 'Suzie'.
The team reportedly suspected the first chassis was deformed, so he got at the wheel of another monocoque for the Spanish grand prix in May.
And – still struggling to match on-form teammate Daniel Ricciardo's pace – Vettel used yet another RB10 at Monza last weekend, which the German driver initially said felt "a little better".
Dr Helmut Marko told Germany's Sport Bild: "The chassis in Monza was actually an older one that was used in testing at Silverstone. It (the change) was more for psychological reasons.
"Now he's going to get a brand new one."
Marko said that while Vettel looked initially competitive at Monza, even outqualifying Ricciardo, "with the harder tires he had inexplicable problems".