This week's Grapevine brings you information fresh from the paddock on: 'Close Call' Forecast for Imola The Wet Tyres Issue

'Close Call' Forecast for Imola

Ferrari's decision to delay introducing their new F2003-GA has opened up at least the next race, leaving the top three teams all with a reasonable chance of winning. Williams, at least, consider this an extension of the early season opportunity before their rivals finally get their new cars on the road. In principle, they see their car as the best package at this circuit, despite game theory analysis failing to bear this wisdom out.

Based on current form this season, and their recent history at Imola, both McLaren and Ferrari are being accorded the best odds to win. Ferrari were completely dominant last year in the same car, and they had a very solid test session there in February - though the car that broke the lap record so impressively was the new F2003-GA, rather than the F2002. Michael Schumacher might be having his worst start to a season, but Barrichello is driving the wheels off the car, and the World Champion's run of poor luck is expected to change. McLaren have been in impressive form so far this year, making the most of every opportunity that has presented itself, picking up all the balls anyone else has dropped. Both their drivers are firing on all cylinders, and promise to deliver a result at every event, provided the car is up to the job. So far, the MP4-17D has been impressively fast and reliable, appearing to be a respectable match for Ferrari's F2002.

Williams' prediction for Imola turns on the interaction of the two biggest factors - the weather and the tyres. A hot track should play towards Michelin rubber. As track temperatures come down, there is a big overlap where neither manufacturer has an outright advantage - Bridgestone exhibiting better consistency against a Michelin performance edge, barring a drop off period - with Bridgestone holding the best of it at lower temperatures. Should it rain, then Bridgestone's intermediates show best on a damp or nearly dry track, showing excellent endurance, whilst Michelin's come in to their own in wetter conditions.

Air temperatures over the weekend are expected to be around 16-19°C, with a chance of showers on Saturday, and some cloud cover on Sunday. Even if there is no cloud, traditional wisdom says track temperatures should favour the Ferrari-Bridgestone combination.

Running a heavy fuel load carries a big penalty at Imola - each ten kilos adds about four tenths to the lap. However, passing is not easy, with processional races the order of the day, so normally two-stops is considered the best compromise. Front runners normally avoid being involved with stragglers by running a longer first stint, to be sure those behind have stopped, or fallen far enough back to complete the stop without encountering them on track.

This means that the new qualifying format is going to make life very interesting when it comes to deciding strategy. Single stopping teams, or those intending a long first stint, will pay a big price in terms of grid position, as the difference between fuelling for a stop on lap 20 or lap 30 could be a second and a half over the lap. Based on last year's times, that difference would cost at least six places on the grid.

Williams hopes for Imola are based on the results of the test ahead of the Brazilian Grand Prix. They are expected to introduce an evolution of the BMW engine, offering the drivers a choice between improved power or fuel efficiency, and a revised aerodynamic package that helps resolve instability in corners, without affecting drag. The net benefit, given all the parts add up, should be worth close to three tenths over a lap, the equivalent of an extra three laps of fuel.

Computer analysis of the strategic options available to the team, based on the modifications working, and what the team knows about the F2002 and MP4-17D, sees their chances as better than fifty percent chance a race win, based on correctly guessing Ferrari and McLaren's strategies. Even getting only the Ferrari tactics right leaves the team with nearly forty percent chance of victory. If the competition are expected to make a long first stint, then taking the fuel out of the Williams should see them qualify ahead of the fuller cars on the grid. Pulling out half a second a lap in the race over the opening laps is expected to see Williams ahead after the first round of stops, with everyone coming in around the same lap for their second stop. Guessing at facing a light car, it's more complicated, as the team need to put in more fuel, then adjust the power and economy settings through the race in response to the competition's pitstops. It gets really complicated if Ferrari and McLaren are running completely different strategies.

The important part for pulling this out of the bag is that Williams believe they can guess the strategies of their rivals with reasonable accuracy, based on warm-up times ahead of the event. The team have been comparing the relationship between warm-up lap times and apparent race day fuel loads, discovering a strong correlation over the three events so far. Considering the progress Ferrari were expected to make with the introduction of their new car, Williams see the continued use of the F2002 as something of a gift horse - and an important opportunity to score well at Imola.

The Wet Tyres Issue

The clamour to take more types of wet tyre to events that started at the Brazilian Grand Prix is not expected to disappear. The original reason for the change to a single wet tyre - ostensibly - was that reducing the wet tyre allowance would cut costs for both the tyre manufacturers, who could take a quarter fewer tyres to events, and the teams, reducing the number of wheels they need to buy and carry. In fact, the measure was driven through by the Michelin teams, who feared Bridgestone's advantage in the wet was too great to overcome this year.

However, in Brazil, it became clear very early that the new concept Michelin intermediate tyre has a window of use that extends to a significantly wetter track than Bridgestone's equivalent - offering considerable advantage until the track dries out. Little surprise that the Bridgestone runners, discovering they basically couldn't really run on the fully wet surface, complained soonest and loudest that teams need to have full wet tyres available, too. This is because neither tyre company is prepared to take anything other than an intermediate tyre to races, because they don't really have a full wet tyre that works well on a track that is drying out (they overheat and fall apart) but is too damp to run dry tyres.

The FIA's position is very simple: to Brazil, the teams clearly should have been prepared for heavy rain - it is well known that when it rains there, it rains hard, so failing to take full wet tyres was blatantly bad planning by the teams. The wet tyre rules were intentionally left open, so that the companies involved could take whatever format was most appropriate for a track. it should not have been left to the FIA to deal with the situation by starting the race behind the safety car.

Looking forward, the governing body is considering three options. The obvious one is to accede to the requests of the teams, permitting a return to the 'three types of wet tyre' approach that they abolished in the off-season: given unanimous support from the teams, it can be implemented immediately. On the other hand, they can clarify the wet tyre rule, mandating tread depth and minimum displacement: again, it can be brought in immediately on the grounds of safety, whether the teams like it or not, but it would be very unpopular with the tyre manufacturers. Lastly, the option remains to leave the rule unchanged: if a manufacturer makes the wrong wet tyre choice, they'll struggle to keep up with the competition, so they won't keep doing it. And if everyone is on roughly the same tyre type, then even if it is not the best for the conditions, it will be a level playing field.

Given a priority for safety, the FIA's preferred route forward is to maintain a single tyre. Whilst it seems counterintuitive that safety is served by running on the 'wrong' rubber, there is a case for it. In order to prevent aquaplaning and control the car, as the water gets deeper, the driver increasingly needs to keep down the speed of the car. The slower the car is travelling when an accident occurs, the less momentum is involved, and the safer the driver will be.

Of course, making the race unpredictable and adding the spectacle of drivers struggling to keep their cars on the track is entirely beside the point.