Lewis Hamilton has again questioned Formula One’s 2017 regulations and has warned overtaking will be difficult this season. On his third day of testing at the Circuit de Catalunya Hamilton said new downforce-focused rules will make passing under race conditions difficult.

“When the design came out the engineers said this is the wrong design, this is the wrong way,” he said. “They said it is going to make the cars faster, it is going to give us more downforce but it is going to make the cars harder to follow.” He said that has now been borne out with track time in Barcelona: “When you are behind it feels one way for a second, then you have a cross wind you’re not expecting or you lose front-end grip and you have to lift and then you never get close enough. I was behind several different cars and it was not easy.”

The cause is turbulent air in the wake of the leading car caused by increased aerodynamics that are part of new regulations Hamilton has acknowledged makes the cars better to drive. “We have these cars that look fantastic and they drive amazingly but, as you get behind another car, it has pure air in front and the car behind [is] in the dirty air,” he said. With Ross Brawn suggesting a non-championship F1 round to experiment with new formats for the sport on Wednesday, Hamilton also suggested that might be a consideration if the lack of passing becomes a major issue.

“The way these cars are and the direction and the design they go, it makes it difficult for us to overtake and people complain that we don’t overtake,” he said. “You have to come up with some different scenarios for races. Look at Monaco, you can’t keep doing the same race format, you just can’t overtake there. Maybe they need to do something to spice it up.”

The new rules were intended to make cars faster and more difficult to drive. But, on the evidence of testing, although speeds are up and times are down, it is not particularly appreciable by fans watching on television.

Worse still, the evidence so far is that, while the cars are more difficult to drive, – and there is a consensus among drivers that they are a real physical challenge – there is little that outwardly suggests this is the case and so the intent to improve the spectacle has not been achieved. If it is at the further cost of a decrease in overtaking, the sport’s attempt to reset itself will be in trouble.

Hamilton’s team-mate Valtteri Bottas set the fastest time on day three of testing with a 1.19.705, two-tenths up on the Ferrari of Sebastian Vettel but intriguingly at this early stage of testing the German’s time – so close to the Mercedes – was set on harder rubber, suggesting the Scuderia have some genuine pace as well as some already rock solid running under their belt.

Hamilton did not challenge the quick times, using his afternoon at the wheel to complete a race-length simulation run, the second Mercedes have completed in three days and another early indication that their new car is as reliable as the championship-winning iteration of the past three years. Fernando Alonso finally managed some proper running in the McLaren after two days of engine problems, with the Spaniard completing 72 laps. Williams endured another costly day and may now have cause for concern after their new driver, the rookie Lance Stroll, whose career thus far has been bankrolled by his father, went off track early in the day and then put his car in the barriers in the afternoon. It was the 18-year-old’s second incident in two days.