Merhi feared he couldn't re-adapt to single-seaters after DTM

The 2011 F3 Euro Series champion raced in the DTM for Mercedes in 2012-13, but after missing out on a place in the manufacturer's line-up for 2014 he turned his attention back to single-seater racing.

Speaking after his maiden FR3.5 win in Russia last weekend, the Spaniard revealed that his initial struggles to get back up to speed in an Aragon test had him fearing that he would not be able to adapt after two years away from single-seaters.

"When I first came back from the DTM for a test I said it was impossible to drive," said Merhi. "Too much downforce, too much grip.

"My first lap was 10 seconds slower than the other people were doing and I said 'I cannot go 10 seconds quicker'.

"It was amazing for me how quick you can go with these cars, I was really surprised by it."

The 23-year-old, who sits fifth in the FR3.5 standings after taking a win and a fourth last weekend, added that it was only in the gap between the two pre-season tests at Aragon and Jerez earlier this year that he was able to get on terms with the Dallara-Zytek racer.

"After the first test I was used to the speed and the g-forces, but it was pretty hard," he said.

"The first time I drove it I thought I should stop because I couldn't drive it - it's too quick for me.

"If you don't drive these cars you're not as strong physically, and you can't train for it without driving it.

"Afterwards I got stronger, and I made a quick recovery, and so far this season things have looked quite good."