Pirelli rally manager Mario Isola has conceded that the choice of tyre for this weekend's Rally Argentina, the fourth round in the 2008 FIA World Rally Championship could be far from ideal.

All the drivers' in World Rally Cars will have to use the hard compound Scorpion gravel tyre, in accordance with the latest FIA regulations and while the choice was approved by all the teams, it could prove difficult to get sufficient grip in them if conditions turn out to be cold and wet.

"This choice of this tyre for the event is not without its drawbacks," Isola confirmed. "But the main thing is that all the drivers are in the same situation, with the same tyres in the same stage and weather conditions.

"It's important to point out that the decision to run the hard tyre in Argentina was approved by all the manufacturers and the FIA's technical department [along with Pirelli's engineers] back in November last year, as part of the plan to use all the different types of rubber that was agreed by everybody."

Asked about the event in more detail, Isola added that it is a difficult one for the rubber.

"This event presents the tyres with a considerable challenge, thanks to the soft and medium-soft surfaces - which are often sandy - and the cool temperatures on some of the stages that are nearly 2000 metres high," he explained.

"There's even a risk of finding some snow, as has occasionally been the case in the past. Whoever is able to exploit the Scorpion tyres best in all the different conditions, whilst avoiding the sharp rocks by the side of the road, will be in a strong position to make the difference over their rivals."

Citroen's Sebastien Loeb meanwhile is amongst those to have concerns: "The major unknown factor concerns how our tyres will perform," he added.

"We are forced to run hard compound Pirellis which isn't ideal for Argentina's sandy, low-wearing stages. We will need to find a set-up that gives us as much grip as possible."