Amazing google results - still confused!

I am working on a huge application at the moment that requires a whole load of replacements in a text string (Think replacing TLA with Three Letter Abbrev’s)

I googled to see if there was a faster PHP method than str_replace().  The results on the first page gave me a chuckle and a headache.

Here is the link to the search result page

So - Is str_replace faster than preg_replace? or is it that preg_replace is faster than str_replace???

Who knows? Google certainly doesnt…