As a follow up for Should I finance a used car or pay cash? Will taking a loan improve a credit score? Does it matter how long it takes to pay off the loan? I wonder if taking a loan and paying it off in a month will give a boost to a credit score
Imagine that your normal mode of using credit gets you a score of X. As time goes by your score trends upward if the positive items (length of credit) outweigh your negative items. But there are no big increases or decrease in your score.
Then you make a one time change to how you use credit. If this is a event that helps your score, there will be a increase in your score. If it is bad thing your score will drop. But if you go back to your standard method of operating your score will drift back to the previous range.
Getting a car loan for a few months to get a bump in your credit score, will not sustain your score at the new level indefinitely. Overtime the impact will lessen, and the score will return your your normal range.
Spending money on the loan just to buy a temporary higher credit score is throwing away money.