Daniel Ricciardo has admitted he is "surprised" Lotus is still struggling so much with its Renault engine.
Following the post-Bahrain test last week, Lotus’ Romain Grosjean slammed the situation as "not acceptable", after both himself and teammate Pastor Maldonado struggled simply to run the E22 amid ’power unit-related’ issues.
The similarly Renault-powered Red Bull’s Ricciardo, however, said he is "surprised" to hear the extent of Lotus’ ongoing troubles.
"It is not very reassuring to see another Renault powered team encountering such difficulties," the Australian is quoted by the French-language F1i.
"We also had a few problems with the V6 turbo in the tests, but nothing too serious," Ricciardo added.
"While we can make further progress on reliability, I am surprised that they (Lotus) are still facing so many problems."
Indeed, Renault’s Remi Taffin said ahead of the Chinese grand prix that the French marque, after a difficult opening few months of 2014, is now beginning to "hit our stride".
"While we know that the others are still ahead, we have made some good progress in the last two races," he explained.
"At the test in Bahrain we tested several new software modes that will see us closer to the limits of the power unit than before," added Taffin.