Mercedes says its decision not to supply its customers with its latest spec of Formula 1 engine for the remainder of the season is out of concern for compromising their performance.

The German manufacturer introduced its “phase four” power unit at the Italian Grand Prix in September, using its remaining seven development tokens on a combustion upgrade. Results have primarily been positive, but there have been reliability issues along the way that Mercedes is eager to eradicate before it passes on the updated system to customers Williams and Force India.

“It is very much an R&D exercise which should enable us to develop in a certain direction for next year,” said Wolff. “It is very difficult to put the customer teams in a situation where technically it could prove to have difficult situations in races – technical problems – and we’ve had some.

“It’s for the benefit for all of us we head in the right direction in 2016, and this is the exercise we are doing around that.”

Mercedes feels it is using itself as a guinea pig over the closing races of 2015 to ensure next year’s engine is as bulletproof as it can be.

“In a certain way we are the testbed,” said Wolff. “That’s a fair way of putting it. You have to weigh up the risks and rewards of such an exercise.

“If you add up all the points, it’s better to have a steeper learning curve with the risk of the technical challenges kept in one team.”

One of the other difficulties for Mercedes in producing a new engine for its customers involves the development of the parts.

“You can’t underestimate, if you’re changing significant parts of the engine, how long it takes to make enough bits to supply,” added Wolff.