More new engine parts for Hamilton 'is unlikely'

Grid penalties at Mercedes

"We are simulating all the races until the end of the year," Shovlin says to Sky Sports. "There's balance and risk of reliability issue. The thing you definitely don't want to do is fail during the race and take a penalty anyway. Then there's the performance element, because the power unit lose horsepower over their life."

So why was the decision made not to replace the other engine components? "The ten place penalty is the bit that most contributes to the reliability element. And the performance is the ICE itself, it's better to take ten places than start from the back," he explained.

Hamilton opts for Turkey

The Turkish Grand Prix looks set to be a weekend where Mercedes are quite strong, especially based on the first free practice. Nevertheless, the choice was made to just take the grid penalty here. "Working out how easy it is to overtake is hard. In your own mind, you know which tracks are good for passing. Sochi has a long straight but we were struggling with understeer, that made it tricky. Hamilton, you remember in the GP2 race, he felt there was lots of opportunity here."

If Hamilton disappoints in qualifying and he only finishes fifth or sixth, the obvious thing to do would be to change all the parts. Shovlin doesn't want to do that though. "That is unlikely. It's fairly intrusive work to change elements during race weekend. We're happy with the decision we've made so far and that's likely what we will stick with," says Shovlin.

Duel with Red Bull

With the gap in the World Championship between Hamilton and Verstappen just two points, an engine change is anything but ideal. Still, Shovlin is enjoying the battle. "It's nice to have the competition, the years in the past it was much easier to win the championships, but it wasn't as much fun as it is this year. Every win means more when you're racing a fierce competitor in Red Bull."