Bridgestone Motorsport has revealed the tyre specifications it will bring to rounds four through seven of the 2010 Formula One world championship, with an emphasis falling on longevity.

Despite calls for softer tyres to be introduced in a bid to force teams to make additional pit-stops after the lack of excitement in Bahrain, Bridgestone has confirmed that it will be taking its hardest compound to three of the four races in question, and re-introducing the gap between compounds for the other in a move to provide a harder option.

In a change to the previous year's regulations, the number of sets of dry tyres available for each driver at a grand prix changes from seven of each compound to six of the harder 'prime' compound and five of the softer 'option' compound, but last year's policy of having two distinct temperature working ranges is maintained, with the hard and medium having a higher temperature working range than the soft and super soft options.

The Chinese, Spanish and Turkish race weekends will now see teams provided with the hard and soft compounds, while the Monaco Grand Prix will see the gap between compounds reintroduced after being abandoned last year, with the supersoft option being joined, for the first time, by the medium compound.

"Deciding which tyres to bring to a grand prix is always a difficult decision, especially as we don't receive advance notification of the exact weather we will see at the race circuit over the three days of running," head of motorsport tyre development Hirohide Hamashima admitted.

"Tyre performance in Bahrain was good, however we remain vigilant and safety is the overriding concern for us. Shanghai and Barcelona are both quite severe circuits and Istanbul, as we have seen in the past, is particularly severe. This is why we are bringing the hardest allocation whilst still leaving a gap in our range between the two compounds.

"For Monaco this year, we will have a gap in the allocation too, which is a change from the two softest compounds which we have brought here previously. We have a harder prime compound for Monaco because of the heavier fuel loads and longer stint lengths that the current rules encourage. We believe this allocation should provide a reasonable and interesting difference between prime and option tyres for this event."

Bridgestone's announcement comes even as the F1 rumour mill suggests that the tyre manufacturer is being lobbied to spice up the action by going more extreme on its options.

According to speculation doing the rounds on the eve of this weekend's Australian Grand Prix, the FIA has stepped into the breach to request that more marginal tyres be supplied at future rounds in a bid to force teams to make more pit-stops and also pit cars on vastly different tyres against each on track.