"The basic power unit is the same for all of the clients, but each installation is unique" - Rob White, Renault's technical chief.
Jan.24 (GMM) Not testing at Jerez next week is a setback for Lotus.
That is the view of the team's engine supplier Renault, despite Lotus saying it will not be disadvantaged by the absence because other users of the French engine - Red Bull, Toro Rosso and Caterham - will be in southern Spain collecting shared data.
But Rob White, Renault's technical chief, said that reasoning is not quite right.
"The basic power unit is the same for all of the clients," he is quoted by Italy's Omnicorse, "and the information will be shared.
"But each installation is unique," he insisted.
"Of course, simulations are possible," White added, "but you can't understand everything with simulations alone."