Tyres, not fuel, vital under new 2010 F1 regime

When pit stops were timed around fuel loads the timing of the stops was planned before the race, but not so now.

"It's going to be much more of a reactive situation this year," Brawn said. "Not much you can plan, you'll have to react in the race to what you see. It's going to be quite tricky to sort out the strategy.

"If you come in too soon for your first set of tyres can you make the second set last the whole race? It's going to be fascinating how the strategy in the stops will work out. It is completely different to last year."

In cases where qualifying is dry and the race is in rain - or vice versa - all cars will get new tyres for the race and not those used for qualifying.

With no refueling - a cost-cutting measure due to the expense of each team hauling fuel rigs around the world - each car will have a much larger fuel tank this season. That has caused a redesign that makes the cars almost a 30cm longer than in 2009. Some teams have tried to capitalise on this by building up the rear bodywork so that it extends from the air intake above the driver's head to connect with the rear wing.

The number of tyre sets allocated to each car over each GP meeting will be cut from 14 to 11. Teams won't be able to get around this by skipping practice and hoarding them for qualifying and race, as one set must be handed back to race authorities after Friday's first practice session and another two after the second practice, regardless of whether they were used. So big teams and small teams alike will do a comparable number of laps on Fridays.

PREMIUM ON WINNING

Another key rule change is the points system. The 10-8-6-5-4-3-2-1 system has been scrapped in favour of 25-18-15-12-10-8-6-4-2-1.

That puts more of a premium on winning. The old points system delivered the second-placed driver 80 percent of the points collected by the winner. Now it's 72 percent. Whether that provides more incentive for the second-placed driver to chase down the leader remains to be seen.

Ten points-earning placings rather than eight will provide more interest for the midfield and tail-end competitors and give even struggling teams something to fight for and something to show for their efforts.

Qualifying will follow the same three-stage format, with adjustments to allow for the expansion of the field from 20 to 24 cars. The number of competitors eliminated after stages one and two will be increased from five to seven, still leaving 10 drivers in the final qualifying stage.

Front tyres have been narrowed from a maximum width of 27cm to 24.5 and wheel covers have been banned but double diffusers will again be here. And, just like last year when they caused much legal argument, there is again the potential for challenges to stewards over how teams have interpreted rules which regulate the design of the diffusers which manage airflow under the car.