Both can buy the same car. They're priced very differently, and the right answer depends on the car, not just the borrower.
A car loan is usually secured, the lender holds an interest in the vehicle and can repossess it on default. A personal loan is usually unsecured, priced on your creditworthiness alone. Security lowers the lender's risk, and that discount flows to you: secured car loan rates commonly run several percentage points below unsecured personal loan rates for the same borrower.
Newer cars from dealers or with clear title are ideal security, so they get the best rates, plus larger loan sizes and longer terms if wanted. On a $35,000 loan over 5 years, a 3% rate gap is roughly $3,000 in total interest, real money for the same car.
Old cars that fail lender age caps, private sales some lenders won't secure, cars needing repairs bundled in, or borrowing amounts below car-loan minimums, here the unsecured loan's flexibility earns its higher rate. Personal loans also leave the car unencumbered, which matters if you plan to sell it soon.
Ignore headline rates. Get the comparison rate for each real offer (it folds in most fees), then put both into the calculator as separate scenarios and compare total cost of loan, not monthly repayment. A longer-term personal loan can show a smaller repayment while costing thousands more overall, the totals expose it instantly.
Car under ~7 years old, dealer or clean private sale, borrowing $10k+: the secured car loan is usually cheaper. Car older than lender caps, tiny loan, or you value a clear title: price the personal loan. Either way, the structure decision is worth as much as any negotiation, choose it deliberately.