- Pirelli's tires have become biggest talking point of Formula One season
- Supplier's test driver says teams have been struggling to find right strategy
- It has allowed some of the lesser-known drivers to make their name
- Pirelli's motorsport head says company decided to make tires more prominent
It can be argued that the biggest star of the Formula One season so far is not one of the six world champion drivers on the grid, it's not one of the legendary teams taking part -- it's not even one of their design geniuses.
The biggest talking point this year is the humble tire. Not because it has extraordinary qualities never seen before in motorsport rubber; quite the opposite, in fact.
Sole supplier Pirelli has purposefully provided product that breaks down quicker than ever. Seven-time world champion Michael Schumacher told CNN they are "like driving on raw eggs."
The result has been seven different winners in eight races as drivers struggle to find the best way to conserve their allocation.
"One of the key points of the season is that Pirelli has been very aggressive and made tires to wear that much during a race," the Italian company's test driver Lucas di Grassi told CNN.
"When you decrease this grip level, when you decrease this contact by wearing the tire a lot, you cannot put the power down, you cannot brake, you cannot corner efficiently enough and you lose performance.
"It has been difficult for the teams to find the best strategy, and that has been key to all the overtakings and the excitement of the races."
Di Grassi gave CNN an insiders' look into Pirelli's tires ahead of this weekend's British Grand Prix at Silverstone.
"It has very little to do with a road car tire, actually," said the Brazilian, who had one season in F1 with the former Virgin Racing team (now known as Marussia) in 2010.
"This tire is made to produce an enormous amount of grip, five times more than a road car and to last much less. A road car can last for 30,000 kilometers and an F1 race is only 300. This tire is made to last between 100 and 150 km."
Schumacher is struggling to restore the dominance he had at Ferrari when Bridgestone dominated the F1 tire scene, though the 43-year-old German's third-placing in Valencia last month suggests he is finally learning to manage the rubber.
Meanwhile, other lesser-known drivers are taking the chance to make their name on the circuit.
Schumacher's Mercedes teammate Nico Rosberg claimed his first career win in China, Williams' Pastor Maldonado did the same at the Spanish Grand Prix, while Sauber's Sergio Perez and Romain Grosjean of Lotus have earned their first podium placings.
Former world champion Kimi Raikkonen has proven quick to adapt on his return to F1, but the driver who has taken the best advantage of the situation is Fernando Alonso.
Faced with the prospect of a season struggling to compete in an ill-equipped Ferrari, the two-time titleholder has stunned experts by moving to the top of the standings with two wins and two other podiums while never finishing outside the top 10.
"It's exactly what makes the difference between a world champion and a common racer," Di Grassi said.
"You can see that Alonso has done an amazing job to understand the tires from the beginning of the season until now.
"For a racing driver one of the most difficult things is to get the most grip out of the tire because you have to feel it, actually have to feel that corner before you arrive there, you actually have to feel that brake so you know how much speed you can carry -- and that's totally dependent on the tire performance.
"And on the other hand it is very difficult for you to understand how to go as fast as possible but also preserve the tire, sometimes to drive at 90-95% to extend the life of the tire."
Pirelli returned to F1 as sole tire supplier in 2011 in a three-year deal after Bridgestone ended its involvement in the elite division of motorsport.
Its head of motorsport Paul Hembery admits there was a conscious decision to put tires in the limelight.
"We always have a tough job getting people to talk about tires. In a competition situation, battling another manufacturer, when you're winning no-one talks about you, but if you're losing you can be sure people will blame it on the tires!" he said in an interview with the magazine of the Caterham F1 team, which CNN sponsors.
"In a control tire situation, such as we have, unless you're having issues with safety they don't get talked about at all. This was our way to try to become a discussion point of the weekend. It helps justify the investment you make in the sport."
Hembery said that, even without the Pirelli factor, the 12 competing teams are a lot closer in performance this year.
"In past seasons we have seen some cars, even at the front, having maybe a half-a-second to a second advantage over the next cars. This year that gap covers 15 or 16 cars. That we didn't foresee," he said.
"It's obviously very interesting to see so many cars in the mix. It's good that we're not sitting here with a third of the season over knowing who's going to win the championship."
Caterham's drivers Heikki Kovalainen and Vitaly Petrov have yet to register a point this season, but the UK-based team's technical director Mark Smith has been enjoying the challenge.
"It provides an opportunity for us -- on a given day, on a given circuit, in the right ambient conditions -- to perform a little bit beyond where we are expected to perform," Smith said.
So what can the drivers expect at Silverstone for Saturday's qualifying and the race on Sunday?
"It is one of the fastest tracks of the season and this means for the tires, a very high energy load, cornering, braking and acceleration," Di Grassi said.
"My top two tips are: use the soft compound for qualifying for optimum grip and best performance; and for the race, mix between the hard and the soft, also saving the tires as best they can, and attack at the right time."