MSRP is correct: Mercedes is looking after the engines, they can easily pull ahead but if that results in failed engines; they'll have deadly grid penalties down the road, which will lose them the championshipIf they didn't have to worry about "only 5 engines per year", the 30 seconds gap to the field would have easily been much more.
http://www.formula1.com/inside_f1/rules_and_regulations/sporting_regulations/8689/fia.html
c) Should a driver use more than five of any one of the elements a grid place penalty will be imposed upon him at the first Event during which each additional element is used. Penalties will be applied according to the following table and will be cumulative :
Replacement of a complete power unit = The driver concerned must start the race from the pit lane.
The first time a 6th of any of the elements is used = Ten grid place penalty.
The first time a 6th of any of the remaining elements is used = Five grid place penalty.
The first time a 7th of any of the elements is used = Ten grid place penalty.
The first time a 7th of any of the remaining elements is used, and so on = Five grid place penalty.
Replacement of a complete power unit = The driver concerned must start the race from the pit lane.
The first time a 6th of any of the elements is used = Ten grid place penalty.
The first time a 6th of any of the remaining elements is used = Five grid place penalty.
The first time a 7th of any of the elements is used = Ten grid place penalty.
The first time a 7th of any of the remaining elements is used, and so on = Five grid place penalty.