Buying a new or used vehicle may be the biggest purchase you make this year. To prepare, you may come up with a list of questions ahead of time to ask the dealer.

However, just as important is knowing what not to say to a car salesman.

Why not? Because what to say — and what not to say — will help give you an edge when negotiating and get you the best price.

1. “I really love this car”: Car dealers know you’ll be willing to pay more for a car you love. Admitting how much you’re in love with the car makes them hold firm on the price or jack up the price. Stay calm and don’t show emotions. Make it clear if you don’t get a good price, you’re willing to walk away. If a salesperson isn’t yet sure you are a buyer, they are more likely to lowering the price. Otherwise, you’ve tipped the scales in their favor instead, and they will be telling you how the car is a big seller and he can’t take less than a certain amount.

2. “My credit isn’t that good”: Regardless of your credit rating, you should definitely shop around for the best interest rate from a bank or credit union before go to any dealership. If you absolutely must finance through the dealership and you have less than stellar credit, don’t admit you think your credit is poor. This could make them think you’ll agree to a higher interest rate. When it comes to financing with the dealership, make sure the number of years and final purchase price on the contract are what you were expecting.

3. “I’m paying cash”: More than 84% of people who bought new cars in a recent year used financed. Don’t tell the salesperson too early on you intend to pay cash. If dealers assume you’re going to finance the car, they may offer you a better price because they’d make up the difference with the in-house financing. Breaking the news to them later in the process could save you quite a bit of money.

4. “I need to buy a car today”: If you rushed over to the dealership because your car just died, it might be best not to let the salesperson know. This is a red flag you’re desperate to drive off the lot with a new car today — and you’ll likely end up paying significantly more for it.

5. “I don’t know anything about cars”: This might be a car salesperson’s favorite thing to hear. They may try to tell you all the extra features you absolutely need to have, and be sure to emphasize how much you need the extended warranty. Do your research ahead of time so you already know what you want on the car and pass on the extended warranty. Salespeople will be able to tell if you already have some knowledge about the vehicle and what features you want.

Bonus Tip: Don’t ever work with a sales person who asks if you are leasing or buying and how much can you afford per month. Instead, talk about the bottom-line price. They might be quoting you a monthly price on a 60-month loan or a 66-month loan. They might or might not be factoring in the interest charges.

Lauren Fix, The Car Coach® is a nationally recognized automotive expert, media guest, journalist, author, keynote speaker and television host. Post your comments on Twitter: @LaurenFix or on her Facebook Page.