There are several aspects I don't understand about teams who build engines for their competitors. Take for example Mercedes AMG who build engines for other teams like Sahara Force India, Williams Martini Racing and so on.
Since the engine is optimised for the remainder of the vehicle, wouldn't this mean that only Mercedes AMG has the optimal chance to get the best configuration? In other words, wouldn't the team building the engine clearly favour and have the best relationship with their own F1 team?
Could they not put secret features in the engines which make them perform worse for the other teams? For instance, take advantage of a different chassis and make it perform worse in that case? I'm not saying this is what they should do, but rather, is there anything in place to prevent this?
