
While Buemi was not penalized for obvious unsafe release during pit stops in race one, his car has been found underweight during a post race inspection.
His second car (the one he used after pit stops) has been found to be under the minimum 880 kilos. It's the car that had to be completely rebuilt after his heavy crash in practice. Renault e.dams team had to rebuild the car completely, using not only a new monocoque, but also new battery (that was the reason for his 10-place grid penalty) and gearbox.
FIA noted that in their official communication of the penalty, adding that "that there was insufficient time to weigh the car after the rebuild". Renault e.dams team added 7 kilos of ballast to the car to compensate for any discrepancies in weight versus the original car, but it has not been enough. They calculated the car to be 3 kg over the limit, while it was 3 kilos under – possibly due to difference in (mandated and standardized) battery weight.
Buemi lost 12 points he got form race on in Montreal – Di Grassi now leads by 18 points going into last race (today 16:00 local / 22:00 CET). As there are only 29 points left on the table (pole position, race win and fastest lap) Buemi has a big mountain to climb to defend his championship.