The term is the trap
Stretching a loan makes the monthly number smaller and the total cost bigger — a $30,000 car loan at 8.5% costs about $616 a month over 5 years ($6,940 total interest) but $372 a month over 10 years ($14,600 interest). The longer loan "saves" $244 a month and costs $7,700 more. For cars especially, matching the loan term to how long you'll keep the car avoids the classic upside-down position of owing more than the car is worth.
Before you sign
Compare on the comparison rate, not the advertised one — application and monthly fees on personal loans can add the equivalent of 1–2% to the real rate. Check for early-repayment penalties (many fixed personal loans have them; most variable ones don't). And if the loan is for debt consolidation, the maths only works if the old cards actually get closed.