Mercedes reveal the reason for Russell's shock disqualification

Mercedes driver George Russell was stripped of his brilliant race victory at last Sunday's Belgian Grand Prix after his car was found to be 1.5 lighter than what the sporting regulation determines. F1Technical's lead journalist Balazs Szabo explains that reason for Russell's shock disqualification.

Having lacked pace on the opening day of the Belgian Grand Prix, Mercedes driver George Russell had pulled off an unlikely win during last Sunday’s race at Spa-Francorchamps. The Briton started from P6 on the grid, and committed himself to a one-stop strategy to take his third F1 win.

However, after the chequered flag, Russell’s car was found to be underweight, with the stewards subsequently excluding him from the results – meaning team mate Lewis Hamilton took the win.

Expanding on the disqualification during his Akkodis-sponsored race debrief, Mercedes trackside engineering director Andrew Shovlin explained: “[It was] obviously very disappointing and unfortunate, particularly after he'd driven such a strong race to win from so far back."

“Right now, we're trying to understand exactly what happened. A lot of that involves us getting the weights of all the different components.

“The car can lose quite a lot of weight during the race. You get tyre wear, plank wear, brake wear, oil consumption. The driver themselves can lose a lot. And in this particular race, George lost quite a bit of weight.”

Although it is rather difficult to answer how much of a gain Russell secured with the underweight car, it was definitely only a tiny advantage compared to his rivals. You can assume that an additional weight of a single kilogram leads to a loss of 0.033 seconds per lap at the flowing, fast, challenging Spa track.

The gain depends on when he started to "enjoy" the benefit. Had his car completed the entire race distance of 44 laps at the Circuit de Spa-Francorchamps underweight, he approximately gained a total of 2.2 over the race distance.

Had his car completed only the second stint under the minimum weight, the gain was significantly smaller. After the race, it was supposed that the issue was down to his one-stop strategy.

If his car was underweight only during the second stint due to the tyres, his total gain was around a tiny amount of 0.4 seconds during the entire race.

Expanding on the gain through underweight car, Shovlin said: “In terms of pace at the start of the race, it's nil because George's car and Lewis's car start the race at the same weight.

"Now, obviously, as George's car was losing weight faster than Lewis's throughout the race, there is an associated gain with that, but you're into the hundredths of a second per lap.

“It will be very small, because when you're talking about amounts, like one or two kilos, they don't amount to a lot of lap time.”

Shovlin revealed that Mercedes suspects that plank and tyre wear, plus weight loss by George Russell himself, may have contributed to his car being under the weight limit.

“The cars started the race the same weight,” added Shovlin. “Lewis and George were both weighed after qualifying. The cars were within 500 grammes.

“George's was the only one that had the problem, and it's because things like the tyre wear was much higher. It looks like we lost more material on the plank.

"We'll collect all that data, though, and look at how we can refine our processes, because clearly we don't want that to happen in the future," concluded the Briton.