Lenders try very hard to be responsive to car loan applications. Delays in financing lead to delays in picking up the car, which may create inconveniences that drive customers (and car dealers) crazy.
For that reason, a car loan is usually decided within two to three business days. Many lenders are even providing approvals on the same day, but you should be cautious with these offers. Take some time after receiving your offer to ensure that you are getting the best deal you can, and not just the fastest. A large national bank may be able to give you an answer in 60 seconds, but the terms and fees may not be as favorable as the ones from a local credit union that takes a couple of days to come to a decision.
The timeline for approval can be lengthened if the borrower doesn’t provide information in a timely manner, or if there isn’t sufficient information about the car being purchased, or if the borrower finds that they will need a cosigner in order to get the loan.