Don't McLaren produce their own car engines now, including for the incredibly impressive P1? Surely at this rate developing their own must be a better option than sticking with Honda.
The issue is going from impressive engines in road cars, or even other series race cars LMP series or Indycar ones, and F1 engines is as big a leap as making toast, and cooking a fugu banquet while blindfolded, and simultaneously trying to complete a rubix cube.
Honda are very successful at making engines. For everything. Road cars, sports cars, race bikes, boats, planes, lawnmowers, you name it, Honda can make a brilliant engine for it. Its what they do. And yet, they have struggled to make a competitive and reliable engine for F1 because its a bigger challenge than anything else.
Their main issue is they started a few years behind everyone else, so catching up is an almost impossible task, until engine regulations change, or are at least stable enough for everyone to catch up. Mercedes, Ferrari and Renault are all constantly developing their engines, so Honda have to work even harder, just to gain a few tenths on everyone else. McLaren are also a very successful manufacturing company, but starting now, at essentially the 6th year of these engines development, is pointless. You might as well not bother and power it with the drivers feet, you wont get close to anyone.
I dont know what McLarens best plan is, but at this moment theyre kind of stuck in a "Honda or bust" scenario because if they take a Merc engine, it wont be the same spec as the works car, which means they will be at a disadvantage and less likely to beat them.
