The computer-based complexities of modern vehicles are beyond the average driver’s ability to understand — and your mechanic knows it. They can easily convince you that you need to spend a ton of money to keep your car up to speed.

Repair shops and dealerships are in business to make a profit, and even if they’re not unscrupulous, it’s not always in their best interest to steer you toward a lower-cost alternative to a common issue, service or repair — even when one is readily available.

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You can’t possibly learn all the details about every system in your car, but you can brush up on the most common and avoidable traps. Here’s a look at the ones to watch out for from experts in the industry.

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You Don’t Need To Change Your Oil as Often as You Might Think

Modern advancements in oil chemistry, engine materials and fuel-delivery systems have put much more distance between necessary oil changes. But drivers don’t always know that — and repair shops are rarely eager to let them in on the secret.

People are still running on outdated recommendations that you should get your oil changed every 3,000 miles or so. According to Edmunds, modern cars often only need an oil change every 7,500 to 10,000 miles, and some can even go up to 15,000 miles.

According to Car and Driver, the best bet — especially when your car is new and under warranty — is to abide by the manual’s instructions, not the mechanic’s recommendation. Kelley Blue Book estimates the average oil change costs between $35-$75, or $65-$125 for synthetic.

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Avoid a Bells and Whistles Oil Change Upsell

On the same topic, every oil change outfit will have a series of different tiers or levels of service, with increasing prices the more you add on. If you know that your car just needs a basic oil change and there’s nothing else wrong with it, or you’ve recently topped up fluids or changed an air filter, you can save yourself money by declining those “premium” services.

However, if you’ve ignored routine maintenance for a while you might want to opt in to a full service oil change, but educate yourself on your car’s needs to avoid paying for what you don’t need.

Don’t Let Worn Brake Pads Turn Into Expensive New Calipers

According to Cars.com brake pads should last for 30,000 miles with urban use and 70,000 or more with light use. When they go, AAA says you can expect to pay about $100-$300 per axle to replace them, or $200-$600 for the front and rear pads.

But for many drivers, that’s just the beginning.

It’s not uncommon for a mechanic to suggest you need overpriced and often unnecessary add-ons like caliper replacements or rotor resurfacing. Your calipers really only need replacing if there is visible corrosion, rust or damage, according to PowerStop Brakes.

Family Handyman warned that buying calipers you don’t really need is the No. 1 unnecessary upcharge to avoid. Even if a caliper is faulty, chances are good that a cheap set of slide pins and some lubricant are all that’s needed to get it back into working order. If you go in for brake pad repairs and the mechanic suggests expensive caliper replacement or even a full system replacement, get a second opinion.

Premium Tires Are Rarely Worth the Upgrade

When the penny test fails and you can see the top of Honest Abe’s head through your worn-out treads, you know it’s time for new tires. But since you change them so infrequently, maybe it’s worth splurging on high-end rubber.

Probably not.

Once again, if the tire shop is the one suggesting you need these tires, chances are they’re just upselling you.

According to Burt & Brothers Tire Service, you’re better off buying mid-range tires, which, their blog said, is the best value for anyone who is just doing your average style of driving. “Expensive tires are rarely good value, meaning that you will pay for more than you need. There is no great value in buying premium tires to get high mileage…” their website states

Change Your Transmission Fluid, but Politely Decline a Flush

Because they’re notoriously expensive to fix and replace, drivers are correctly terrified of damage to their transmissions — and mechanics know it. That’s why they often recommend a transmission flush instead of the standard fluid change.

My Garage Auto & Tire in Nebraska ranks flushes as one of the top services you don’t need, calling it a quick, easy moneymaker that doesn’t address some of the most important aspects of sound transmission health — and the experts agree.

“Don’t bother with engine or transmission flushes,” said Lauren Fix of Car Coach Reports, who has fixed, rebuilt and raced cars throughout her career. “These techniques are often recommended to clean up dirty engine oil or transmission fluid. They’re not worth the money.”

And they’re not cheap.

According to Car Advise, the average flush costs $26 and $65 — twice as much as a transmission fluid change. That’s because a flush consumes 12 to 22 quarts of fluid, as opposed to five to seven for a change.

In Fix’s experience, basic preventative and proactive upkeep precludes you from ever needing this service.

“If you do the maintenance work recommended in your owner’s manual, you won’t need to do this,” she said.

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This article originally appeared on GOBankingRates.com: 5 Common Car Maintenance Services To Avoid Wasting Your Money On