A personal loan includes both secured loans (auto, boat, etc) and unsecured loans. The difference being the "secure" loan has collateral that "secures" it; whereas the "unsecured" loan has no collateral.
I would think your credit score would do the same for an unsecured personal loan as it would for a secured auto loan.
It is only the poor who pay cash, and that not from virtue, but because they are refused credit. - Anatole France
FICO Scores (1/6/13): EX 642 and TU 670