Each company rates your credit history differently, so there could be differences in your APR or interest rate, depending on your score. FICO and VantageScore use information from the three major credit bureaus: Equifax, Experian, and TransUnion. Both companies have different categories and ranges.
The higher your credit score, the lower your interest and APR will be. Typically a score of good or above will get the best interest rates for loans as they see these borrowers as less of a risk. If you are preapproved for a loan and are unhappy with your rate, you can attempt to improve your credit before purchasing your car.