Top 10 Vehicle Maintenance/Repair Myths Your Mechanic Tell You

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Tips & Advice

vehicle repair myths

Going to the auto service shop can be like entering a foreign country after thirteen in-flight bottles of tequila and a bag of stale peanuts. An auto mechanic can talk at you, but you aren’t picking up all the lingo.

“Your exhaust manifold needs its tubular joints welded to the intake valve on the left tire.”


Exactly. Understanding the inner workings of an automobile, especially a modern one, is no easy task. Cars haven’t gotten simpler over the years. There is more technology packed into today’s cars than was used to send the first man to the moon—and we can’t even agree on how we did that either.

More than a few myths have been drummed up over years to give auto mechanics a slight upper hand because of the mystery surrounding today’s cars. Here, we debunk 10 of those myths.

1. 3,000 Mile Oil Change

vehicle repair myths

Right out the gate, we’ll attack one of the most common myths surrounding the automobile—the oil change. The 3,000-mile rule of thumb came about in the 1960s and 1970s when engine and engine oil technology wasn’t the science it is today. Engines and oils were still evolving back then. Today, there is no reason a modern car cannot go 5,000 or more miles before an oil change. Even many of today’s cars have oil-life monitoring systems that tell you when you should change your oil. No more tacky window stickers reminding you you’re six months over due for an oil change. Of course, the oil industry would tell you to change your oil every 3,000 miles, that is money in their pocket.

2. Fuel Additives and Cleaners

vehicle repair myths

In some instances, a fuel additive is necessary, especially when you are storing a vehicle for any length of time. Is it necessary to pour some fuel cleaner into your new Bimmer? Simple answer, no. Gasoline does produce nasty, gummy deposits, but since 1995, gasoline has also had detergents to clean those gunky buildups. No need to spend money on adding more.

3. Engine Tune Up

vehicle repair myths

This is a great way for a mechanic to extort money from you for just kicking some tires and replacing a few spark plugs. Back in the olden days when cars ran on leaded gas and child safety seats were still a concept, engines worked in tune with many adjustable parts that needed to be perfect for the engine to run right. Today, the car’s computer regulates all those annoying control systems. There is no need to adjust the fuel-to-air mixture because your car can do it automatically for the given conditions.

4. High-Octane Fuel Is Better For Your Car

vehicle repair myths

High-octane gas doesn’t work the way one would think—it actually burns slower than lower octane fuel. Why? Sports cars, which are the general recipient of the expensive drink, compress fuel and air in a high compression cylinder to extract the highest amount of performance out of it. This tight squeeze can cause lower-octane fuel to prematurely combust, causing detonation or knocking, and rob the car of power and performance. Lower octane engines and fuel don’t use a high compression cylinder so engine detonation and knocking aren’t lartge concerns. No matter what your crazy uncle tells you, you won’t get more performance out of your car by using a higher octane fuel, just a lighter wallet. 

5. DIY Is the Same As Taking It To the Shop

vehicle repair myths

We've all been guilty of trying to save a few dollars every now and then doing something ourselves. That patio project? No problem. Call your friend Frank, buy a six pack of an adult brew and get it done on a Saturday afternoon, right? Sadly, that’s not how life works. The six pack will be gone in an hour. It will take three Saturdays and four Sundays and Frank will only be there for one of them. That’s how car repairs work as well. While general maintenance is easy enough to do, many of us don’t have the trained eye of a mechanic. While we lumber along changing the oil, a cracked spring or loose ball joint can go unnoticed, causing a potentially dangerous situation in the future.

6. Keeping A Warranty Valid Means You Have To Use The Dealership

vehicle repair myths

One of the biggest thing dealerships do is try and scare you into using their service department. One way they do this is telling you that you must use the dealership’s service department if you want the precious warranty to remain intact. Any reputable shop, independent, franchise or otherwise can perform the work without voiding your warranty. So, if you can get a cheaper deal somewhere else, take it.

7. Inflate Tires To the Pressure Shown On the Tire's Sidewall

vehicle repair myths

All tires have a maximum pressure listed on the sidewall and there is a common thread that tires must be filled up to this maximum pressure. That’s wrong and dangerous. Most tires can go on a multitude of differing vehicles. Because of their versatility, it is best to fill up the tires to the recommended pressure for that car.

8. You Should Replace a Tire If You Run Over a Nail

vehicle repair myths

Replacing tires is not cheap. A new tire can cost well over $100 and the tiniest of nails can deflate one in minutes. But going out and buying a new tire isn’t the only option. If your tire has a puncture, a good patch will not only save you money—most patches cost around $20—but will quickly and safely put you back on the road again.

9. You Can Save On Car Wash Fluids By Using Dishwashing Detergents

vehicle repair myths

Washing a car is vital to its longevity. Road grime and road salts, if you live where it snows, can cause havoc on your car, so regular washing is important. However, going inside to grab the dish soap could be just as disastrous. Dish soap is too harsh for cars’ wax and using it can strip that protective coating away.  It’s best to pickup special automotive soap at the auto parts store. 

10. Flush Coolant At Every Oil Change

vehicle repair myths

This is another old-school idea that has somehow lived on into the modern day. This is an expensive and unnecessary service that cars simply don’t need. Stick to the service schedule recommended for your car, and your coolant will be just fine.

Since having CarShield, Bill has had 2 claims on his Ford F250 to save over $2,000 in repairs.
Since having CarShield, Bill has had 2 claims on his Ford F250 to save over $2,000 in repairs.

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