Looking ahead to this weekend's Spanish Grand Prix, Red Bull's chief designer Rob Marshall, reveals that Sebastian Vettel will have a new chassis.

Seeking to close the 46 point gap to championship leader Nico Rosberg, not to mention hold off his own ever improving teammate, Vettel will have a brand new chassis for the start of the European season.

Revealing the move, which should have happened at the start of the season, Marshall says that Daniel Ricciardo will also get a new chassis "some time around Silverstone".

Asked if this is a benefit, Marshal said: "It shouldn't be, as the idea is that they are all the same. Drivers don't always want to change them – they can get attached to a particular chassis and when they are on a good run they like to hang on to it for as long as possible!

"From our point of view we'd rather give them one or two new chassis during the season that we have been able to check out in the factory using various testing methods," he added.

"Normally we make four or five chassis during the year, maybe six, so it wouldn't be unusual for each driver to change at least once or twice during the year. Normally they would use at least two."

The start of the European season usually sees a host of upgrades from all the teams and the world champions are no exception.

"The cars are upgraded almost every race," says Marshall, "some of the upgrades can be large and some small, such as little tweaks on the front wing, some details of the bodywork or upgrades to the car's cooling system.

"The Spanish Grand Prix is probably the first opportunity for teams to bring a big upgrade to the car during the season. The cars have been on the other side of the globe for the first quarter of the year and teams' R&D departments will have been busy coming up with large upgrade packages to bolt on the car for the first time in Spain. They will often compromise whole body work packages, so the floor, engine cover, front wings and rear wings, potentially new suspension components and various other bits and bobs."

Asked if upgrade times are planned at the start of the season, he replies: "There are a couple of races that stand out as being obvious ones for a major upgrade. That's the first European race for logistics reasons and also the last European race, as it's the last opportunity we have to bring performance to the car without having to fly it out around the world."

Asked about the specific upgrades for this weekend, Marshall wasn't quite as forthcoming.

"All the teams will have updates," he replied, "and we can see what they all are in a few days."

Chris Balfe