As efforts continue to find a testing solution for the 2013 season following the twin debacles of the Mercedes test scandal and the Silverstone tyre blowouts, Pirelli has had to continue to use its outdated 2010 Renault test car for tyre development.
F1's lucky escape from tyre fiasco
Hembery believes the biggest stumbling block is teams' fear that rivals will get an unfair advantage.
"That has to change. We have to have some things done differently," Hembery said.
"You can do a lot of things on simulators and even there I cannot use just one simulator, because then I will be told I am biasing one team over another.
"The paranoia levels are high because the competition levels are high, but at a certain point that has to be let go to let us do our job.
"We are not interested in helping one team over another, we just want to do our job.
"We don't care if we do tests with five different teams, one after the other."
He said the controversial Mercedes test at Barcelona in May had ironically shown just how vital such running could be for an F1 tyre supplier.
"It sounds terrible when I say it but the best tyre test we have done for three years was with Mercedes at Barcelona..." Hembery admitted.
"Looking at it in a selfish way, from our point of view, it was the best tyre test we have done.
"We had hard cars, hard drivers, working professionally and giving us exactly what we want."