Ron Dennis believes McLaren is "not receiving the best engines" from Mercedes and says that will change with Honda.

Already an engine supplier to McLaren among other teams, Mercedes returned to F1 as a constructor in 2010 and has taken full advantage of the 2014 regulations to become the dominant team. However, Dennis believes the extra information that the works team gets regarding how best to make this year's Mercedes power unit work is an explanation to the performance advantage it has over other teams.

"There are lots of people who take great encouragement from finishing or qualifying in third, fourth, fifth, sixth, seventh..." Dennis said ahead of the Japanese Grand Prix. "This team has never done that, and the one thing that jumps at you if you look at all the qualifications of this year is the time difference between the Mercedes-Benz works team and the other teams. And by and large it's always in excess of a second, putting aside the pace which they can generate in a grand prix when they're on their back foot.

"What does that mean? My opinion - an opinion held by many people in our organisation - is you have no chance of winning a world championship if you are not receiving the best engines from whoever is manufacturing your engines.

"A modern grand prix engine at this moment in time isn't about sheer power, it's about how you harvest the energy, how you store the energy and effectively if you don't have the control of that process - meaning access to source code - you're not going to be able to stabilise your car on the entry to corners etc. and you lose lots of lap time."

And Dennis believes McLaren's switch to Honda next year will help it close the gap in terms of power unit performance, but warns it is likely to take time.

"Even though you have the same brand of engine that does not mean that you have the possibility to optimise the engine. So you've got to put yourself in to a position where you have the best engine available. That's what we've done over approaching years."