The Mercedes Formula 1 team have admitted to making multiple mistakes during the recent Japanese Grand Prix which hampered drivers Lewis Hamilton and George Russell.
In a dry qualifying, Mercedes were sixth and eighth at Suzuka with Hamilton ahead of Russell as the W13 was set-up with a high downforce configuration that left it vulnerable on the straights.
This proved evident when Hamilton was stuck behind Esteban Ocon for a majority of the restarted race on Sunday - but failing to pass due to the Alpine being quicker in a straight line.
On top of that, Russell felt hamstrung by double-stacking during the mad rush for Intermediate tyres shortly after the restart.
Trackside engineering boss Andrew Shovlin has now admitted to the multiple mistakes in Mercedes' latest race debrief.
Rear wing decision was wrong
"We decided to stay at our highest downforce level, and part of that decision was that it was actually giving us the best lap times in the race," explained Shovlin.
"We were going to get high [tyre] degradation in the dry, but we had also seen this rain that was coming in on Sunday and we felt that in a wet race that might be a benefit.
"As it happens, the DRS was never enabled, and that meant that overtaking was very, very hard and perhaps the right decision would have been a lower downforce setting."
The W13 has been plagued by relative uncompetitiveness on low-downforce, circuits which require straight-line speed such as Spa or Monza.
It is an in-baked performance deficit that the team has been unable to engineer out of the troubled design - with Shovlin confirming that it is something the team needs to "fundamentally" get on top of.
"But fundamentally, one of the things that we need to improve on the car for next year is to get the car to have more downforce at the lower drag levels," he said.
"Then we can race those lighter wings and still be competitive in the corners."
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Russell decision was wrong
Russell was also left frustrated during the race after being forced to wait behind Hamilton while he was serviced and lost positions.
With hindsight, Shovlin says that the team should have waited to box the younger Briton.
"We've gone through all the timing of that and we have concluded that no, it wasn’t the right decision [to box Russell.]
"We should have done what George was asking which was to give him the lap in in clean air.
"Now, we had seen that the Intermediates were a lot quicker, so on the Wets you would have lost time on track.
"But the problem was George and Lewis were a bit too close for us to be able to do the pit-stop without losing some time and that time ultimately cost George the position to [Yuki] Tsunoda and possibly even the position to Lando [Norris].
"It gave him a bit more of a challenge to deal with having to pass those cars to try and find any clean air."
Hamilton would finish in fifth, still behind Ocon, while Russell was eighth, having been pipped by Fernando Alonso on the final lap of the race after the Alpine driver pitted for a fresh set of Inters.
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