Using the official site for each team I've worked out the number of race wins, world drivers', and world constructors' titles per each team's time in the sport. As the points system has changed so many times over the years it's a very dubious way of stating who is the most successful team ever. The results are to four decimal points.
McLaren:
Victories per Grand Prix Entry:
631 Grands Prix contested/155 victories = 4.0709
World Drivers' Championships won per seasons competed in:
41 seasons contested/11 victories = 3.7272
World Constructors' Championships per seasons competed in:
41 contested 10 victories = 4.1 OR 41 seasons contested/8 victories = 5.125
Ferrari:
Victories per Grand Prix Entry:
758 Grands Prix contested/201 victories = 3.771
World Drivers' Championships won per seasons competed in:
57 seasons contested/15 victories = 3.8
World Constructors' Championships per seasons competed in:
49 contested 15 victories = 3.2666 OR 49 seasons contested/13 victories = 3.7692
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Given the political influence of Formula One, I think it's reasonable to use the second set of figures pertaining to the constructors' title. Therefore, McLaren have more victories per Grand Prix entry, regardless of your views on the politics of the sport; Ferrari are first in terms of more drivers’ titles being won per season entered, again, regardless of the politics; If you believe, as I do, that McLaren really have ten constructors’ titles, they are first. If you believe McLaren have only eight Ferrari are the most successful in that department.
This is the most disingenuous post I've seen in a while from somebody who has absolutely no idea what he's talking about, i.e., statistics!

You title your stats with Victories per GP entry, but then go ahead and divide the GP entries by the victories - exactly the opposite of what you claim to show with your calculation. Of course this way McLaren appears to look better because the resulting number is higher. However, it's the wrong number and actually means GP entries per victory, i.e., how many GP's did they need to achieve a victory (and the lower the number, the better the performance, so compare McLaren and Ferrari and weep).
The correct stats would be (I just did it for victories, but you can do it for the rest if you like):
155 victories per 631 GP contested = 0.2456 for McLaren
and
201 victories per 758 GP contested = 0.2651 for Ferrari.
I strongly suggest to stick your nose into this (or similar) book
http://tinyurl.com/yv8cbabefore you post ANY other stats of yours laced with amateurish mistakes.