Renault engine performance boost "surprising" - Prost

The French manufacturer endured two difficult seasons in 2014 and 2015, a situation that nearly led to it parting ways with Red Bull Racing.

However, Renault made a significant leap with its power unit over the winter, before introducing an upgraded engine spec at Monaco, which will be available to all four of its drivers in Canada.

Red Bull secured its first pole position since 2013 in Monaco, where Daniel Ricciardo could have won the race if not for a pitstop blunder by his team.

"I think everybody can be a bit surprised because it is typical racing," said Prost, a Renault ambassador. "It is quite surprising considering that for sure the last two years were quite tough.

"But that is typical F1, things can change and sometimes what you get what you are paying for: a decision - or no decision - two of three years before.

"So it is a very good surprise, very positive."

While Red Bull is now fighting near the top of the field, Renault's works outfit is struggling to be competitive despite using the same engine.

Prost reckons the fact that Red Bull is so strong is actually good news for Renault, as it validates the progress made with the engine and allows the French squad to focus on improving the chassis.

"It is a very positive thing," he said. "At least you know the engine is working well and it can be very good for the people making the engine, very good for the image, very good for Red Bull.

"It means you can concentrate, and it gives a nice motivation, a nice vision for the future. It is almost like this part is working, so we can do even better."