David Coulthard cannot understand why his old McLaren team are so far off the pace as Formula One prepares to launch the new season here on Sunday.

McLaren are not expected to compete for a podium place in the opening races after a number of setbacks in the three testing sessions in Spain – the worst of which was Fernando Alonso’s crash which has put him out of the Australian Grand Prix at Albert Park and led to speculation over the cause of the accident. In testing McLaren lagged behind not only the title favourites Mercedes but also Ferrari, Red Bull and Williams.

Coulthard, who had nine seasons with the Woking team between 1996-2004, said: “I just can’t get my head around the situation and all the difficulties they’ve had. Honda [who supply McLaren’s power unit] are behind right now and it will take them time to catch up. But they had an extra year to develop their engine. Last year, when the new engines were introduced, Ferrari and Renault didn’t do as good a job as Mercedes.

“But while all that was happening Honda had already signed to McLaren and had a year learning and developing, so it’s really weird. There’s stuff going on there which is very unMcLaren like. But then they’ve had a pretty bad run for years now.”

Last season McLaren’s drivers Jenson Button and Kevin Magnussen finished on the podium in Australia but failed to do so for the rest of the season with the team battling to finish fifth in the constructors’ championship ahead of Force India.

Coulthard thinks McLaren, who last won the constructors’ championship in 1998, are too distracted by making road cars to focus fully on the challenge of Formula One. “Ron Dennis [the chairman of the McLaren Group] has this desire to grow the group and launch cars and run a Formula One team. But no one can give 100% to two things. It’s physically impossible.

“They brought the F1 sports car out in the 1990s and then the Formula One team dropped off for a while. Then the Formula One team came up before they did the SLR with Mercedes, and then the racing team went down. Then it went up again and then, recently they brought out another road car, the P1, and the F1 team has gone down again. There is definitely this cycle.

“You need investment to develop a road car project. And if you are putting time and energy into finding money for the road car the less time and energy you’re putting into the Formula One.

“The reason Red Bull won four championships is not because it’s an historic name in Formula One but because they invested in the right guys and they were all totally focused on one thing.

“It was the same thing at Ferrari when they had the Jean Todt, Michael Schumacher, Ross Brawn period. They were totally focused and they created this winning machine. And when that focus disappeared the team lost their way.

“Last year there were changes at McLaren but it was a very disappointing year for them. They had all this restructuring going on and they had a good engine but they just didn’t have a good car. They might not have the best engine now, in the Honda. But you’ve got to believe their design team can do a better job than they have done. They’ve got amazing design facilities. If this was a competition to decide who had the best facilities to design the best piece of kit McLaren would win the world championship every year. Ferrari is a pretty tired and run-down place. Red Bull is an industrial estate in Milton Keynes. It’s not sexy.”

Coulthard believes McLaren have the right man to turn things round in the racing director, Eric Boullier. “I’ve been really impressed by Eric and his focus. There’s clearly a guy there who knows how to bring everything together. But where are the sponsors on the car? You can’t run these things on fresh air.”

Coulthard has also been bewildered by the Alonso situation, in which the driver spent three days in hospital following his concussion but was then declared not to be injured by Dennis, before being advised not to race by doctors.

“It does not add up. You can take at face value the information we’re being given. But are we being given diluted information? It’s possible but it’s a risky strategy because these things eventually come out.”

David Coulthard will be part of the BBC team at the Australian GP on Sunday 15 March. Follow live on Radio 5 live and watch highlights on BBC1 at 1.15pm