- Monaco GP - Qualifying
ERS issue slows Vettel
An Energy Recovery System (ERS) issue hampered Sebastian Vettel's qualifying lap at the Monaco Grand Prix, which he estimated was worth around 0.4s in lap time during part of the session.
Vettel qualified fourth on the grid, under 0.2s off the team-mate Daniel Ricciardo and 0.5s off Lewis Hamilton in second. He said the problem was cutting his ERS boost intermittently, and although it came back a bit for the end of the session, he still was not able to run at full power.
"Unfortunately in Q1 we had a problem with the ERS half way through the run," he said. "Basically, I lost the ability to discharge at the maximum rate and initially halfway down the straight I was just relying on the ICE [Internal Combustion Engine], but it was a bit hit and miss to be honest, sometimes it was working, sometimes it wasn't working on the same straight.
"Especially early in acceleration when you lose out it's quite costly in terms of lap time, and we basically had the same problem until the end of qualifying. Towards the end we were able to run a little bit below the maximum, which gave us a more consistent discharge, but still not full power."
Asked how much time it cost him, he added: "I haven't seen any data, but the only comparison I saw was in Q2 compared with Daniel, and from what I saw it was in the magnitude of 0.4s.
"If you don't have the boost, which you can compare probably to KERS usage last year out of the corner, that means you lose initial acceleration but also the whole straight. Plus we didn't have it for all the straight, so it was basically both initial acceleration and top end. Sometimes as much as you would usually upshift to sixth or seventh and with the problem you didn't have to do the upshifts because I was slower."