Di Resta admits fitness will be biggest challenge in race

The 31-year-old qualified 19th after taking over the unwell Felipe Massa's Williams ahead of qualifying at the Hungaroring, and despite having trained to F1 standards and being race fit thanks to his full-time DTM drive, he is anticipating a draining race.

"Physically," he said when asked what will be the most difficult challenge to deal with in the race.

"I'm trained, but you're tense and you need to learn to relax and let the muscles relax. It's like any winter, the first day you come back – you think how did I ever drive these things and find it so easy.

"Even when I had the winter off and drove a DTM car, the first day you hurt because you're hanging on, using every muscle.

"I probably had my hardest grand prix round here in 2012, it was hot, so I'm not expecting it to be easy tomorrow.

Di Resta described the Williams team's task in qualifying as one of simplifying the learning process so he could get up to speed having never driven the 2017 Williams FW40.

He expects to take a similar approach to the race, although the absence of experience of the car on long-runs means he accepts things could go wrong.

"A sensible pace," he said when asked by Motorsport.com what his objective would be for a good race.

"You could find yourself burning tyres up very quickly, within two laps, and being out of position because you don't know how much slip angle to put in them – it was something I was always quite on the good side of before.

"My style seems to have carried over into this car so far. But I don't know where the cars going to develop, how much front wing I want to carry for the first stint, what tyre to start the race on.

"I'll leave it up to you [the team] and I will just get in the car and do what I've got to do and the best job I can physically do is turning the steering wheel – you do everything else to make it what you think is best.

"Keep it simple and letting me concentrate on pushing the two pedals and turning the steering wheel."

Williams chief technical officer Paddy Lowe is confident the pre-race laps to the grid can also be used to help di Resta to prepare.

"We'll try and do the most we can in the laps to the grid, race starts, position in the box, that sort of thing," said Lowe.

"But it's not as though Paul hasn't race, he does know the basics and he has done many seasons in Formula 1. So I don't think it will take him too much to just refresh himself on those particular details."