When you trade in a vehicle at a dealership, the dealer makes money twice: on the new vehicle you're buying and on the used vehicle you're selling. The trade-in price they offer you has to be low enough to leave room for reconditioning, markup, and profit when they resell it.
This doesn't mean dealers are dishonest — it's just how the economics work. Understanding it helps you decide whether to trade in or sell privately, and how to get the most from either option.
What your car is actually worth
Before you accept any offer for your vehicle, get multiple appraisals. Carmax, Carvana, and Vroom all offer instant online appraisals that are real, no-obligation offers — you can accept them within a few days of getting the quote. These offers reflect true market value and give you a floor for any negotiation.
KBB Instant Cash Offer and similar tools also connect you with participating dealers who will buy your vehicle outright. Getting three or four of these appraisals takes about 30 minutes and sets a realistic baseline.
Private sale: more money, more effort
Selling privately — through Facebook Marketplace, Craigslist, Autotrader, or Cars.com — typically yields 10–20% more than a dealer trade-in or instant cash offer. For a $20,000 vehicle, that's $2,000–$4,000 in your pocket.
The tradeoffs: it takes time (often two to four weeks to sell), you need to manage inquiries and test drives, and you're responsible for the paperwork. You also need to handle the buyer's financing — most private sales are cash or bank check.
For vehicles worth more than $15,000, the private sale premium is usually worth the effort. For cheaper vehicles, the complexity may not be worth the difference.
Getting the most from a trade-in
If you prefer the simplicity of trading in, go in with outside offers in hand. Walk into the dealership knowing that Carmax will give you $18,500 for your car. If the dealer offers $16,000, you can tell them exactly what competing offers look like.
Negotiate the trade-in and the new vehicle separately. Many dealers will offer a high trade-in while padding the new vehicle price, or vice versa. Keeping the negotiations separate — get your best trade-in offer first, then negotiate the new vehicle — makes it easier to evaluate each deal on its merits.
Timing matters: trade in a vehicle when its value is high. If you're considering a trade-in, don't wait until the car develops a problem, needs new tires, or has an upcoming major service. Sell it when it's in good shape and you'll get more for it.