Formula 1 teams are facing a tough call on tyre strategy for the Italian Grand Prix because of the low degradation experienced so far, claim leading team bosses.
Although the small drop off in performance should point towards an easy one-stop strategy, the situation actually appears quite different because of the risk of wearing tyres out.
When drivers experience high degradation, the tyres are changed because their performance has dropped too much - rather than because they are too worn out to continue.
McLaren team principal Martin Whitmarsh says the difficulty teams now face at Monza is judging exactly how far they can push the rubber without it wearing out.
The situation has been further exacerbated by the narrower gauge tyres that Pirelli introduced for this race and last weekend's event at Spa.
"I think there is a fair amount of debate," he said about the strategy call for the race. "There were interesting strategies in Belgium, and we did a reasonable amount of homework on Friday so we have some decent information.
"But in truth I think if you ask Pirelli, I don't think they don't know what we should be doing.
"They are strange tyres in that the degradation [normally] means you have to change them before they are worn out, because their performance has gone.
"With the relatively limited degradation, the next thing you know is you have some carcass exposed and that is not a good place to be. It is a worrying thing I think.
"We have done more homework than most teams. We did a lot of running yesterday and a lot of teams have not done that, so it is a worry that drivers will be out there in a situation where tyres fall off once you see the carcass. It makes it quite tricky."
Mercedes team principal Ross Brawn thinks the tyre situation means that the last few laps of each stint could be critical.
"The tyres are fairly flat, but they do reach a point where they start to degrade quite quickly," he explained. "You have a first stage of degradation which is I think very flat, but then you hit the second stage which can be more severe.
"I think one stop is possible within the flat slopes of degradation but it is quite tight, and I think we will all be looking at the numbers to see how the tyres are behaving to decide what to do.
"One stop is a tradition and it is possible, but there is no point doing a one-stop if your tyres are going off badly.
"I think there is a need to make sure that you finish the race in good shape. I think the last 5-10 laps could be quite important, and if people have changed to the second tyre too early then there is a chance it could be marginal by the time they get to the end of the race.
"You will see some interesting racing, particularly towards the end. It is not an easy one stop, let's put it that way."