A lower rate on your remaining balance can cut the payment and total interest.
An auto refinance calculator shows what refinancing your car loan to a lower rate could save, comparing the remaining payments on your current loan with a new loan on the same balance.
If your credit has improved or rates have fallen since you bought, refinancing the remaining balance at a lower rate cuts both the monthly payment and the total interest left to pay. The calculator compares your current remaining payments with a new loan so you can see the difference in dollars.
Refinancing into a longer term can lower the monthly payment while actually increasing total interest, the same trap as any loan. To genuinely save, keep the new term at or below the months you have left. Also watch that the car isn't worth less than the loan (being 'underwater'), which can make refinancing harder.
If you can get a meaningfully lower rate and keep the term the same or shorter, yes, it cuts the payment and total interest. The calculator shows the savings.
Yes, if you stretch the term. A longer new term lowers the payment but can raise total interest.
An improved credit score, lower market rates, and positive equity in the vehicle all help.
See the exact formula and a worked example on our methodology page.