How it works
A dealer rate markup — the industry calls it dealer reserve or rate participation — is the spread between the buy rate a lender actually approved you for and the higher contract rate the dealership writes on your paperwork, with the difference rebated back to the store as compensation for arranging the loan. It is legal, disclosed only in fine print, and invisible unless you ask: nothing on the four-square worksheet separates the lender's price from the store's surcharge. The mechanics matter because the markup compounds silently. This calculator prices it in dollars: enter the amount financed, the rate your credit union or pre-approval quoted, and the rate that appeared on the contract, and it returns the added monthly amount, the total extra interest across the term, and the markup as a share of what you borrowed. A two-and-a-half-point spread on a $28,000, 60-month loan is about $36 a month — nearly $2,150 in total, roughly 7.7% of the amount financed, pure negotiation room. The defense is structural rather than rhetorical: arrive with outside financing already approved, make the dealer beat that rate in writing, and treat any payment quote that skips the rate as a signal to slow down.
Formula
Extra interest = (payment at contract rate − payment at buy rate) × term | Markup % = extra interest ÷ amount financed
Tips
- Secure a credit-union pre-approval first — it sets the ceiling the dealer must beat.
- Ask for the buy rate in writing; lenders cap markups near 2–2.5 points.
- Negotiate price, then rate, then term — never a single monthly number.
- Watch for the markup returning as 'approval fee' or bundled add-ons.
- Refinance later if stuck: a post-sale refi to the buy rate recovers most of it.
Frequently asked questions
- What is a dealer rate markup?
- It is the gap between the buy rate a lender approved and the higher rate written on your retail installment contract. The lender shares the difference with the dealership as commission for originating the loan. On a $28,000, 60-month loan, a 2.5-point markup costs roughly $2,150 extra.
- How do I find my true buy rate?
- Apply for pre-approval at a bank or credit union before visiting the lot — that quote approximates your buy tier. Inside the F&I office, ask directly which lender approved you and at what rate; they are obligated to disclose it if pressed, and the gap to your contract rate is the negotiable spread.
- Is dealer reserve legal?
- Yes, in most US states, provided the contract discloses that the dealer may receive compensation for arranging financing. What is not allowed is misrepresenting your approval terms. Because disclosure is buried, regulators treat the practice warily — but enforcement rarely reverses signed contracts, so prevention beats complaint.
- Does the markup change if I finance for longer?
- It scales with the term. The same 2.5-point spread on a 72-month, $28,000 loan adds roughly $2,500 versus $2,150 over 60 months, because the inflated rate accrues on the balance for more payments. Shorter terms shrink the dollar damage faster than they shrink the rate itself.
- Can I refinance out of a marked-up auto loan?
- Yes, usually after six to twelve on-time payments. Moving a $28,000 balance from 7.99% back to your 5.49% buy rate over the remaining term saves close to the full markup — around $1,800 if done at the midpoint — minus a modest transfer fee, making refi the cheapest undo button.