In an ironic twist, Honda's technical director, Toyoharu Tanabe has admitted "surprise" at the number of engine penalties the Mercedes power unit is incurring this season.

"I am very surprised they are changing the ICE (internal combustion engine) frequently," Tanabe told reporters. "Actually, I cannot believe what's going on.

"From the PU manufacturer point of view, it's kind of disappointing to get a PU penalty for the driver," he added.

His comment comes at a time Lewis Hamilton has taken a 5-place hit for Sunday's Grand Prix after taking on a new ICE, his fourth of the season.

The Briton joins Mercedes teammate, Valtteri Bottas who recently took on his sixth ICE of the season.

Of course, Tanabe's "surprise" will be seen as somewhat ironic considering the sheer number of penalties McLaren picked up during its disastrous partnership with the Japanese manufacturer between 2015 and 2017, when it was not uncommon for the Woking team's drivers to be demoted grid positions that ran into double figures.

Indeed, at Stoffel Vandoorne's home race in 2017, the Belgian youngster was demoted 65 places, while at this very circuit in 2015, weeks after comparing the Honda unit to that of a GP2 car, two-time world champion, Fernando Alonso famously watched qualifying from a deck chair by the side of the track.

Explaining the decision to change Hamilton's ICE, Mercedes boss Toto Wolff told Sky Sports: "We have deg on the engine that until the end of the season is just going to continue to decrease in power and we haven't yet realised why that is, but we are just seeing it creep down.

"Without going into specifics, every engine is degrading and we've seen that over the past years over 1,000 kilometres there is a certain amount of kilowatts that the engine is degrading. Ours is just degrading much more than in the average of the past years and that increases from weekend to weekend.

"If we keep the engine we are going to for sure not going to be competitive in Saudi and Abu Dhabi," he admitted.

Tanabe is confident that its four drivers can get to the end of the season without the need for further penalties.

"The current plan is we can manage the PUs the rest of the season for all drivers," he said. "We had some accidents during the season and then lose some PUs, but at the moment, we have a sufficient number of units for all drivers."

Asked if he believes that but for the crash damage the Red Bull duo, for example, could have gone the season on three power units, Tanabe replied: "I believe yes."

Honda leaves F1 at the end of the season having sold the IP to its programme to Red Bull which has set up its own powertrain division.

Check out our Saturday gallery from Interlagos, here.