I have to disagree Tom. The Zetec has a history of sticking valves when filled with heavy weight oil. You most likely do not have this problem as you generate a significantly greater amount of heat than the average Focus, and, therefore, thin the oil much faster than most. While there may have been some changes to the motor that have eliminated this problem (like the elimination of hydraulic lifters), why take the chance?
While I will not be one to say 5w-20 or nothing, I will state that there is no reason to run such a thick oil for a daily driver. What possible benfit could there be?
wow, that's thick. i've never used royal purple. not sure how much or if it's better than M1. personally, i can't see it being that superior to M1 like some people say. especially for the price. free things are nice but, if you can't use it...
Although it's quite heavier than the recommended oil I think it'll be fine if you have your car on a 3000 mile oil change interval, especially given the cost. Since it's already thicker than the recommended oil I wouldn't run it any longer than I'd have to. Better yet, trade it in for the correct weight