One cannot compare oxygen bleach verus chlorine bleach because they simply are not the same in terms of whitening/stain removing.
Chlorine bleach will remove protien and discolor orgainc/tannin based stains in five minutes or less, even in cold water. Times are much faster the higher the water temperature increases.
OTHO oxygen bleach, if percarbonate will bleach in cold water but needs long contact times. Perborate alone will not bleach well at all in cold water, but activated perborated bleaches can but again need long contact times. All oxygen bleaches have an increase in bleaching power by about 20% or each 10 degrees in water temperature. To achieve the whitening/stain removal power of chlorine bleach with oxygen bleach in the same amount of time, the water temperature would have to be in excess of 150F or higher.
As for difference between European detergents versus North American, will say that in general the later are designed to work under high diluted conditions (high water levels found in top loading washing machines), with short cycles (again top loading washing machines), both condition suit the primary way most Americans wash laundry, in top loading machines. Tide for instance uses the perborate bleach activator NOBS, which is quite aggressive,but made to work in the rather short amount of time top loaders have for an average wash cycle. In Europe the primary bleach activator is TAED, which is slower acting thus suited to longer wash cycles. It should be noted many versions of Persil and other detergents are moving away from perborate bleaches, thus the need for activators and to sodium percarbonate bleach, which does not need an activator as it will bleach in warm and cold water.
As for dilution ratios when using UK/European detergents in the United States, one must remember most parts of Europe have water hard enough to chip teeth. Even the hardest American water would be "soft" by European standards,thus one can use less, much less detergents.
Being as all this may, our first front loader was a Malber that did not heat water, and had rather "short" cycles. Persil by Henkel worked well, but saw no differnece say between it and Wisk tablets or Tide HE. Certianly not enough of a difference to warrant the cost. OTHO when using Persil Megaperls in the Miele, difference is striking. Because the machine fills with either cold or warm water, then heats to hot, along with long wash times it is a true "European" wash cycle, the conditions Persil was designed for and most used under. One tablespoon or less of Persil Megaperls will clean a 5Kg load in my Miele without any additional additives.
Think of it this way: detergents like Tide are "sprinters", in that they have to use all their energy quite quickly to run the race. Persil and other European detergents have along race to run thus pace themselves to provide power until the end.
