How Formula 1 race strategy will be different in 2010

How will banning refuelling affect the racing in F1 in 2010?

By Ted Kravitz BBC F1 pit-lane reporter

Bernie Ecclestone's latest controversial comments about introducing shortcuts to Formula 1 to improve overtaking has focused attention on the latest rule changes to be introduced into the sport.

Ecclestone's idea, dismissed by former Ferrari driver Eddie Irvine on 5 Live on Thursday evening as "horrible", is the latest in a series of proposals by him rooted in his belief that the decision to ban refuelling in 2010 will have a detrimental effect on the racing.

But that will not necessarily be the case - grands prix will look different but strategy, and the use of it, will still play a crucial role.

With just two weeks before winter testing starts in Spain on 1 February, and teams hurriedly putting the finishing touches to their new cars, we take a look at the key factors that will shape the races this season.

FUEL CONSUMPTION

The first big headache for teams will be calculating the exact amount of fuel to put in the car.

Engineers will have had enough time in winter testing to figure out their fuel consumption rates under different weather/track conditions and engine settings, and can use a lot of their data from last year so this shouldn't be a problem.

Where the headache starts is trying to carry as little fuel as possible to complete the race.

Three-second pit stops are the target - some teams think they can do it quicker even than that

Dominic Harlow, chief engineer at Force India, says: "We'll be working hard on saving fuel during the race.

"Even 1% too much fuel could end up costing you a position so it will be critical to carry exactly the right amount. If you finish a race with 5kg excess fuel in the tank, it will have cost you 10 seconds during the race."

So with very tight safety margins and even the temptation to under-fuel their cars in order to be quicker, potentially the biggest embarrassment for the teams will be running out of petrol.

There will be moments when drivers need to conserve fuel to make sure they finish the race - they'll have to slow down as much as they dare, while trying to keep others behind.

Engine mixture settings will be critical: Drivers will be leaning out their fuel mix when they can, for instance stuck in traffic or behind a safety car. This will allow them to enrich it when needed for more speed.

In this regard, Michael Schumacher and Rubens Barrichello may be at an advantage, being the only two drivers in the field who drove in the last non-refuelling season, 1993.

HOW MANY PIT STOPS?

With no refuelling, pit stops will be for tyres only. Remember that rule about having to use both compounds of Bridgestone tyre during the race? That's still in the regulations, so drivers must make at least one pit stop.

Ahead of a meeting of the F1 Commission on 1 February, there is currently a lot of discussion between the teams and the FIA about how many stops cars have to make.

The desire seems to be for two mandatory stops.

This might spice up the show and introduce scope for mistakes, but would remove the intriguing prospect of a driver such as Jenson Button who is easy on his tyres making just one stop, while racing against someone who needs to make two stops because they work their tyres harder.

The opportunity for the tortoise to beat the hare would be lost.

WHEN TO STOP - AND FOR HOW LONG?

Obviously teams want the fastest tyre on the car as much as possible, so there's a lot to be learned over the forthcoming tests about which tyre to run and when.

A basic approach is to run the harder compound first, when the car is heavy with fuel, then the softer tyre later on in the race when the car is lighter and the track has more rubber on it, which will not punish the tyre as much.

Mercedes boss Ross Brawn is acknowledged as a master of strategy

Again, there are ongoing discussions about whether to make cars start the race on the tyres with which they finished qualifying. This looks like it will happen, and will introduce an interesting variable into the mix, forcing front-running cars to try to qualify on hard tyres or race on soft tyres.

Pit stops will be much quicker this year. Teams will be competing in the pit lane as well as on the track, as mechanics look to break records for the fastest pit stop time.

Three seconds stationary is the target; some teams think they can do it quicker than that.

Interestingly, engineers believe the limiting factor in pit stops will be how quickly the mechanics on the front and rear jacks can perform their duties.

The wheels come off and on quite fast; the wheel guns tighten the nut at 3,000rpm and, with 'spinner' wheel covers banned and a self-locking wheel nut, that operation is fairly brisk as well.

So drivers will be waiting for the front and rear jack men to lift the car quickly to allow the tyre men to do their job. The front jack man in particular will have to be quick on his feet at the end of the stop!

Total time lost in the pits will therefore be around 16 seconds at an average circuit.

Traffic will play a major part in deciding strategy with pit stops remaining fluid, being decided by tacticians on the pit wall.

Stopping before a rival you are racing will generally be an advantage - as cars will always be quicker after a stop than before it because new tyres will give extra pace and the fuel load will constantly be coming down.

But the trade-off will be that if you stop too early, then you risk being slow on worn tyres at the end of the race, and vulnerable to drivers on fresher tyres.

In this respect the pit stop window will be much larger than in recent years, when fuel dictated the pit stops.

TYRE WEAR AND FAILURES

In 2009, cars at the front typically started a race with around 50kg of fuel, adding 60kg at each stop on an average two-stop strategy.

This year they will have 170kg of fuel in the car's fuel tank at the start of the race. That's around 220 litres of petrol.

There have been concerns over whether the extra weight of fuel will put tyres under greater strain, leading to more problems.

Pit stops will be much quicker in 2010 without the need to add fuel

But the 170 kg of fuel is far less than the approximately 1,000kg weight already put through the tyres from downforce, so extra fuel weight shouldn't be a factor.

A heavy car, though, will inevitably handle differently, which will have an effect on tyre wear and degradation. How much it affects each car and driver will be interesting to see.

Then there are flat-spots - caused by lengthy periods of locked wheels.

The front tyres are narrower this year, so there is a smaller contact patch on the front wheels. We could well see drivers lock their brakes trying to slow down their heavily fuelled cars for tight corners.

If this happens, teams may be more inclined to change a flat-spotted set of tyres than in previous years, when an extra stop would have ruined their fuel strategy.

Kimi Raikkonen had direct experience of this at the Nurburgring in 2005, when vibrations from a flat-spotted tyre broke the McLaren's rear suspension, costing him the race win.

UNSUITABLE TYRES

As last year, there may be one compound of tyre that doesn't work particularly well in certain temperatures on certain circuits. Both compounds are required, so trying to get one out of the way will be a decision taken on the pit wall when the opportunity presents itself.

Starting a race with an unfavoured tyre might be a tactic used again, especially if a team feels they are out of position or want to get the unfavoured tyre out of the way as soon as possible, as Brawn did in Monaco last year.

606: DEBATE if the commercial rights holder of Formula One can shamelessly propose such a cuckoo idea, then a nobody like me can come up with 'cukooer' ideas and still hold his chin up klotnews

Manufacturers Bridgestone are still undecided on which compounds will be brought to which race and if they will be using consecutive or non-consecutive compounds, something that spiced up the races last season.

Much is still to be decided, but with only 16 days testing in February to get all the answers they need, F1's engineers and drivers have a lot to learn in a very short time.