Dear Car Talk:

I am the original owner of my 2015 Mazda 3 with just under 28,000 miles.

During my recent routine service appointment, the following actions were recommended: replace all four tires ($460, not counting labor), throttle body service ($65) and fuel injector service ($130).

I've had 10- to 14-year-old cars and never had one needing the last two services mentioned above.

What do you think is going on? -- Linda



Well, it sounds like your dealer has a small boat with a payment due. If he had a 38-foot cabin cruiser, he'd be recommending shocks and an exhaust system, too, Linda.

Let's start with the good news.

Your dealer's prices are not out of line. What he's proposing to charge you for each of those services is pretty reasonable, assuming he's selling good quality tires.

The bad news is that you may not need any of those things.

We have a machine in the shop that does the throttle body and fuel injector cleaning. It's called the Motor Vac, but we call it the Wallet Vac. We used to use it a couple of times a week. It would make a big difference for cars that were stumbling and hesitating. But gasolines are so clean these days that I'm not sure I can remember the last time we used the machine.

So, those services shouldn't be needed unless your car is showing symptoms of dirty fuel injectors. The primary symptoms are hesitation on acceleration, or a check engine light that's on and storing a code for a fuel system problem. Otherwise, the cleaning is completely unnecessary.

You may need tires. Original equipment tires on modestly priced cars are often not great quality and do wear out by 30,000 miles.

You might ask around (or check mechanicsfiles.com) for a recommendation of a good, independent mechanic in your area, and get a second opinion on all three of these services.

If a second shop confirms that you need these things, then you'll know your dealer is on the up and up, and you can go back to him with confidence.

If the shop says you can get another 10,000 miles out of these tires, and they have no idea why the dealer is recommending a fuel injector cleaning, you can factor that into your future car repair plans, too.