Gasly: 'Question marks' over reliability of Honda update

Toro Rosso Formula 1 driver Pierre Gasly says "question marks" remain over the reliability of Honda's updated-spec power unit following issues on both cars since its introduction in Canada.

Honda supplied Toro Rosso with its updated engine in Montreal, only for Gasly to be hit with an issue during practice that forced him to revert to the previous-spec power unit for qualifying.

Teammate Brendon Hartley was also sidelined by an engine problem on Friday ahead of this weekend's French Grand Prix, forcing Honda into changes that leave the New Zealander last on the grid for today's race due to the resulting penalties.

Gasly qualified 14th on Saturday in France, but admitted after the session the power unit did not feel as strong as it did in Canada, as well as conceding there were still concerns about its reliability.

"Canada was really promising, but in qualifying was the first time I ran with the new spec this weekend, and it didn’t feel as good as in Canada," Gasly said.

"I am sure there are some explanations but at the moment we don’t really know. We struggled a bit more.

"Reliability is still a bit of a question mark. But I’d rather have full beans and the maximum performance and just go for the performance.

"On my side at the moment in Canada I didn’t have any problem. We still need to do a lot of races with that engine, so that is why we decided to save the mileage on the Friday.

"Hopefully in the race we will be fast and able to overtake like in Canada."