Jolyon Palmer 'gaining in stature' says Renault F1 technical chief

Palmer endured a tricky start to his grand prix career, with several crashes - including on the start/finish straight in Monaco - but he turned things around mid-season.

He made a breakthrough with the set-up in Hungary and though he threw away points there with a spin, he finally got on the board in Malaysia, before finishing his debut campaign strongly.

Palmer also won the battle with Kevin Magnussen for the sole seat that was up for grabs at Renault, following Force India recruit Nico Hulkenberg's appointment.

"I don't know if it took him a while to get his head around Formula 1 in a full-on season, get used to the cars and get used to this car, and how to get the best out of it," Bell told Autosport.

"I don't know if it was just a learning thing for him. It quite possibly was but either way he's shown real progress.

"That's the important thing, whatever the reason behind it is.

"I don't think he's finished with that yet, he's going to keep improving.

"He'll learn from someone like Nico, which is another important factor, and he's prepared to learn which is good.

"He's got an open mind and he's gaining in stature all the time.

"If he keeps developing as he has done in the latter half of the season then he'll do well."

By retaining Palmer, Renault maintains some consistency heading into 2017, when the regulations are overhauled.

Bell said it was "important" to do so as "it is never good when you change two drivers".

He added: "To keep one of them is good for consistency and we're very pleased to have Jolyon with us.

"Honestly from an engineering perspective, it was a very difficult decision between Jo and Kev.

"Jo has certainly improved a lot, particularly in the latter part of the season.

"You can see him gaining confidence and he's just improving all the time.

"It will be a good pairing next year because they are quite different and will bring different things to what we're trying to achieve."