Refinancing an auto loan can trim your monthly payment or save you money on interest, but the decision depends on your credit score, current rate, and how much time remains on your original loan.

The main benefit of refinancing is a lower interest rate. If your credit score has improved since you took out your original loan, or if market rates have dropped, a new lender may offer better terms. For example, dropping from 7 percent to 5 percent on a $25,000 loan can save you thousands over the life of the loan. A lower rate also reduces your monthly payment, freeing up cash for other expenses.

Refinancing also gives you the chance to shorten your loan term. Instead of paying off a 72-month loan over six years, you could refinance into a 48-month loan and pay off your car faster while building equity quicker.

The downsides matter too. Refinancing involves fees and a hard credit inquiry, which temporarily lowers your credit score. Lenders charge application fees, documentation fees, or title transfer fees. These costs typically range from $100 to $300, eating into your savings if the new rate only improves slightly.

Timing matters enormously. Refinancing makes the most sense early in your loan term when you still owe a lot of principal. If you refinance late in the loan, you benefit less since you have fewer months of interest remaining to save. You also need to be careful about extending your loan term to lower payments. While this reduces your monthly cost, you'll pay more total interest and stay underwater on the loan longer.

Shop around before committing. Credit unions often offer lower rates than banks or dealerships. LendingClub, Lightstream, and Marcus by Goldman Sachs all offer auto refinancing, as do most regional banks. Get multiple quotes within a two-week window to minimize