Paul Hembery has some concerns about the Jerez track surface, saying it is "rather abrasive" resulting in shredded and stripped tyres.
The Formula One teams have been in action at the Spanish track since Tuesday, evaluating not only their new cars but also their new Pirelli tyres.
However, Hembery fears the track's surface, which has caused the stripping of tyres, has also not allowed for a true evaluation of the rubber.
"The track is rather abrasive - and is substantially worse than last year," the Pirelli motorsport director told Autosport.
"We have seen quite a lot of shredding of tyres, and there seems to be a lack of bitumen in the track, so we are looking at a very open surface.
"It has meant that what was historically an interesting track from our point of view for doing tyre compound work has proven to be probably dominated by that effect, so we have not seen the differences between the compounds that we would have liked.
"We have still seen peak performances of half a second between different levels, and the hard tyre has been working quite well considering those conditions to get through their work, but there has been this stripping action across the top of the tyres."
Pressed as to whether that meant the teams were not able to get in any 'useful tyre work', Hembery said: "Certainly for tyre evaluations, yes. It is a shame because the weather conditions are not too bad.
"You struggle to get anywhere above 20 degrees in Europe in February, so it is slightly disappointing from that point of view.
"But it is quite a big evolution from last year; it is so far away from anything else you are going to see in terms of macro."
