Son B has been renting an apartment for 4 years and has a credit card. Recently son A took son B shopping for a new car and came back with a a car loan. Son A claims B needs it on his credit report or B will have trouble down the road getting a mortgage. As son B has money in the bank earning low interest, I think he should pay the 6% auto loan off. Is the impact to his credit really worth the interest he would be paying? I would think his credit card payment record, good rental history and a big down payment on house would be enough to get a good mortgage rate.