As we were looking for laundry detergent yesterday, I noted that my wife was quite swayed by brand reputation/impressions than price. She stated that she didn't think one type of detergent really removed stains. I asked if she'd ever consciously been aware of this and noticed, and she said "No."
It's not hard to find some other references like this, such as About's list of top detergents HERE:
These laundry detergents are some of the most effective and efficient available to keep your clothing clean.
- Tide Laundry Detergent
- Gain Joyful Expressions Laundry Detergent
- Purex Complete 3 in 1
- Method Laundry Detergent
- Cheer TrueFit Laundry Detergent
They don't really describe anything about how they came to these conclusions, however.
Question: Is there available evidence in which someone has attempted a controlled experiment evaluating different detergents for their ability to remove (make un-detectable by sight, touch, or smell) stains/dirt? Perhaps in addition, some site that has compared soil-removing ability with price?
Edit: Freebie for an answerer... Consumer Reports apparently tested 50 detergents HERE. The abstract indicates that Tide, indeed, was the best, but that there was a law of diminishing returns at play. Anyone with a subscription who can post some key quotes?