How do you lower your car loan interest rate?

You can lower your car loan interest rate by refinancing with a new lender after your credit improves, adding a co-signer, or negotiating at the time of purchase by arriving with a competing preapproval. Dealer-arranged financing often carries a markup — securing your own financing first gives you a benchmark to beat.

Your auto loan interest rate is driven primarily by your credit score, loan term, lender type, and whether the vehicle is new or used. The Federal Reserve's G.19 Consumer Credit report publishes average rates by vehicle type and lender category monthly — knowing the benchmark tells you whether an offer you've received is above or below market.

Before you borrow: strategies at purchase

Get preapproved by your bank or credit union before visiting any dealership — your preapproval rate is the ceiling you're willing to pay
Bring a competing offer: dealers can sometimes beat outside financing, but only when they know you have one
Choose a shorter loan term (48 or 60 months vs. 72–84): shorter terms typically carry lower rates and build equity faster
Make a larger down payment to lower your loan-to-value ratio, which reduces lender risk
Improve your credit score before applying: paying down revolving balances and avoiding new credit inquiries for 90 days can lift your score meaningfully

After you borrow: refinancing to a lower rate

Refinancing is the most direct path to a lower rate if you're already locked in. It makes the most sense when your credit score has risen since origination, when market rates have dropped, or when you originally financed through a dealership without comparing lenders. See the dedicated guide on how to refinance an auto loan for the step-by-step process.

The co-signer option

Adding a co-signer with strong credit can move you into a lower rate tier if your own credit is thin or damaged. The co-signer shares full legal responsibility for the debt — they will owe the balance if you default. Both parties should understand that clearly before agreeing. The CFPB's co-signer guide covers the legal obligations involved.

Interest rate context — key data

The Federal Reserve G.19 report shows that credit unions historically offer lower average auto loan rates than commercial banks, making them a useful first stop when shopping for financing. — Federal Reserve — G.19 Consumer Credit
The CFPB warns that dealer-arranged financing sometimes includes a markup above the rate a lender would actually charge, meaning the consumer pays a spread the dealer retains. — CFPB — Auto Loans
CFPB research found that borrowers who shopped multiple lenders received meaningfully lower rates than those who accepted the first offer — comparison shopping is the single most effective rate-reduction strategy available at origination. — CFPB — Consumer Financial Protection Bureau

Key takeaways

Getting preapproved at a bank or credit union before visiting a dealership is the highest-leverage rate strategy at the point of purchase
Dealer markup on financing is real — your preapproval creates competition that can eliminate or reduce it
Credit unions consistently offer lower average auto rates than commercial banks per Fed G.19 data
Refinancing after credit improvement is the main lever if you're already in a high-rate loan
A co-signer helps but creates shared legal liability — ensure both parties fully understand the commitment