A 650 credit score car loan is potentially expensive compared with an excellent credit car loan that may have an APR as low as 0%. Borrowers with fair credit, including those with a 650 credit score, may qualify for car loans with an interest rate of 6% on a new vehicle and 10% on a used vehicle. Getting $20,000 in car loan financing at a 6% interest rate and six-year term could translate into $3,864.96 in total interest charges over the life of the loan. Meanwhile, borrowers with excellent credit may qualify for 0% APR car loans. The cost of any car loan could be expensive if the interest rate is high.