Mercedes engine boss Andy Cowell says his team might consider saving one of its engines this year to use as a "performance special" now that five power units are permitted over the course of the season.
The addition of a 21st race on the calendar has upped the allocation of engines per driver from four to five this year, although if a race were to drop off the calendar before the season opener it would return to four.
As a result, Mercedes has been planning on using four power units over the course of the season, meaning it could have one extra engine left over if there are still 21 races on the calendar by the start of the Australian Grand Prix. Asked if the team might save that engine in order to run it at the very top of its potential for one race towards the end of the season, Cowell said it was "tempting".
"Our plans were all based on there being 20 races and therefore four power units - that's what all our targets are based on," he explained. "Depending on how the next two or three weeks go determines how aggressive we are with the running from Melbourne onwards and that will determine whether we plan just to use four and therefore have that bonus power unit, which might help us out if we have a quality issue or might help us out if we want to play a performance special.
"But we'll work all that out in the days before Melbourne. There are long runs going on in the factory and four examples being run here [in testing] to see whether the hardware with the fuel and the lubricant are durable and reliable."
The limit on the number of engines per season is designed to keep costs down and drivers are hit with grid penalties if they exceed more than their allotted number of power unit components for the year. Last season Mercedes and its customers managed to stay within the limit of four, while Honda used as many as 12 power unit components on the two McLarens.