Berlin: Formula One world championship leader Lewis Hamilton will start from the middle of the pack at Sunday's Turkish Grand Prix after his Mercedes team decided to introduce a new engine component in Istanbul.
Hamilton will use a new internal combustion engine (ICE), his fourth of the season, Mercedes said on Friday.
The news did not distract Hamilton from posting a best 1 minute 23.804 seconds around the 5.338-kilometre Istanbul Park circuit in the second practice session of the day having also led the first.
Drivers are allowed only three ICE units per year before penalties are applied.
But Hamilton will not start from the back of the grid like Red Bull title rival Max Verstappen in Russia two weeks ago as changing only a single component, rather than the whole engine, brings just a10-place penalty.
"There is the balance and risk of a reliability issue, and obviously the thing that you definitely don't want to do is fail during the race and then have to take a penalty anyway," Mercedes trackside engineering director Andrew Shovlin told Sky Sports.
"Then there is also a performance element because the power units do lose a bit of horsepower over their life.
"The 10-place penalty is the bit that most contributes to that reliability element and the performance is the ICE itself, so it is better to take 10 places than to start from the back."
However, Hamilton starting in midfield is likely to hand the lead in the championship to Verstappen, who is currently only two points behind in the standings with seven races remaining.
Verstappen, aided by the rain-induced chaos which brought Hamilton victory in Sochi in the last race, fought back to claim second in Russia and minimize the damage to his title hopes.
Now Hamilton will attempt to do the same as he tries to win a record eighth world title as Verstappen chases his maiden championship.
Verstappen was second fastest in first practice but a modest fifth with 1:24.439 minutes in the second session.
Charles Leclerc of Ferrari was instead closest to Hamilton at 0.166 seconds with Valtteri Bottas third in the other Mercedes and Sergio Perez fourth with the other Red Bull.
Leclerc's team-mate Carlos Sainz has also said he will have a full engine change and will start from the back of the grid.
Qualifying for the race is after final practice on Saturday. -- dpa