Not a scientific test by any stretch, but I'm sold on PB Blaster because of it: I normally use WD-40 or Liquid Wrench on stuck fasteners. A year ago, I had to replace the cataltyic converter heat shield on my wife's '95 Civic. I used Liquid Wrench, and although I did eventually get all the fasteners off -- having snapped one bolt, however -- it took me the better part of an hour after spraying everything down and letting it sit for an hour or so. Last weekend, my sister's '95 Integra needed the same heat shield replaced. I was low on Liquid Wrench, and had since given up on WD-40 altogether, so I stopped by the auto parts place and picked up a can of PB Blaster. By all appearances, the bolts were just as rusted/frozen/corroded as the ones on my wife's car. I sprayed each of the four fasteners, went inside and poured myself a Coke, came back out, and I swear those things came off with a six-point socket like they'd been put on the day before. I'm sold.