Should you finance through the dealer or your bank?

Get preapproved first, always

CFPB guidance on this is blunt: get preapproved before you visit the dealer, and compare total loan cost, not the monthly payment. That is not anti-dealer advice, it is just sequencing. A preapproval from your bank or credit union gives you two things a walk-in customer does not have, a real interest rate you already qualify for, and a fallback if the dealer’s finance office cannot beat it. You are never worse off walking in with a preapproval, even if you end up financing through the dealer anyway.

Why dealer financing isn’t automatically the worse deal

Dealers are not simply marking up whatever a bank would quote you. Many manufacturers run their own captive finance arms, and those arms sometimes subsidize rates on specific models to move inventory. When that happens, the dealer can genuinely beat your outside preapproval, sometimes by a real margin. Other times, the finance office marks up whatever rate the lender actually approved and keeps the difference, a legal practice within limits called dealer reserve. You cannot tell which situation you are in without a number to compare against first.

What a market-rate loan actually costs

The average new-car loan ran 6.39% APR in Q1 2026. As a reference point, on a $35,000 balance over an assumed 60 month term, that works out to roughly $683 a month and about $5,981 in total interest, illustrative math from that average rate, not a quote. That is the baseline either the dealer or your bank needs to beat, and the only way to know if they did is to have already done this kind of math, or to ask directly for the total finance charge over the life of the loan.

The failure mode preapproval closes off

Without a benchmark, you are negotiating blind on the one number that compounds for years, the rate. A dealer can quote a payment that feels comfortable while the underlying rate sits well above what your credit actually supports, and you would have no way to know. Preapproval removes that blind spot. It also protects you from a subtler version of the same problem, being told “this is the best we can do” when better was genuinely available, just not offered first because nobody asked.

How the comparison actually plays out

Walk in, hand the finance manager your preapproval, and ask them to beat it. If a manufacturer promotion applies to your vehicle, you will likely see it offered, dealers want to write that loan too, since it can pay them a reserve on top of the subsidized rate. If nothing beats your outside rate, you finance through your bank and the dealer still gets to sell you the car either way. There is no real scenario where bringing a preapproval costs you a better deal, it only puts a floor under a worse one.

When each option tends to win

Dealer financing tends to win when a manufacturer is running a genuine promotional rate on the model you want, since an outside bank or credit union cannot match a subsidy designed specifically to move that inventory. Bank or credit union financing tends to win on ordinary purchases with no promotion attached, especially if you already have a relationship and a strong file, since there is no markup layered on top of the base approval. Neither option is the automatic winner, the promotion, or lack of one, decides it more than the lender’s name on the paperwork.

What a credit union brings that a big bank might not

If you are choosing where to get preapproved in the first place, credit unions are worth including alongside big banks. They are member owned rather than shareholder owned, which sometimes translates into lower average rates and more flexibility on a marginal file, though this varies by institution and is not guaranteed. Membership is usually easier to get than people assume, often just an address, employer, or a small membership deposit. It costs nothing to get a quote from one alongside a traditional bank before you compare either against the dealer.

Watch the finance office after the rate is settled

Even once you have settled who is financing the car, the finance office visit is not over. This is where extended warranties, GAP coverage, and other add-ons get presented, often at their most negotiable prices to a buyer who is mentally already finished shopping. None of these products are automatically bad, but agreeing to them unpriced and unresearched, in the same conversation where you just settled the rate, is how a good financing decision gets undone by a rushed one. Slow down for this part specifically.

A short checklist before you decide

• Get at least one outside preapproval before you shop, even a rough one.
• Ask the dealer’s finance office to quote against your preapproval, in writing.
• Confirm whether any manufacturer promotional rate applies to your specific vehicle and trim.
• Compare total finance charge over the full loan, not the monthly payment alone.

Preapproval is worth understanding in more depth before you start shopping, and if your current loan already closed at a rate you now suspect was marked up, refinancing is still an option. Either way, knowing what counts as a good rate right now is the starting point for this whole decision.

Next steps

Apply for preapproval with your bank or credit union before you set foot on a lot. Bring that offer to the dealership and ask their finance office to beat it in writing. Sign with whichever lender actually offers the lower total cost, regardless of whose name is on the building.