A shorter loan or a smaller payment?

Spreading a loan over more months lowers each payment, because the same amount is split into more pieces. Interest runs for longer, though, so the overall cost usually goes up. A shorter loan works the other way. Each payment is bigger, and the overall cost tends to be lower.

Neither suits everyone. A payment that leaves you short every month is hard to keep up, however much it saves in the end. Putting the monthly figure and the total for two or three terms side by side makes the trade easier to see.