Renault decided against reintroducing its KERS system for this weekend's Turkish grand prix.
Having dropped the controversial energy re-use and power boost technology for Barcelona and Monaco, team engineering boss Pat Symonds said that decision would be "reassessed" ahead of Istanbul.
Unlike Monaco, where even getting the engine's normal power down around the twisting curves is difficult, the Turkish layout features three long straights.
Some calculations predict that at Istanbul, KERS-equipped cars could wield an advantage of up to three tenths of a second per lap -- and several metres in the run to the first corner.
But after Friday practice at the circuit, Fernando Alonso confirmed that the R29s do not feature KERS at this event.
"Yes, you are right that we have some straights, but also some high speed corners, where the weight distribution is very important," he told F1's official website.
The 27-year-old said he is expecting to qualify near the bottom end of Q3 on Saturday.