Car Maintenance Myths That Could Be Costing You Money

When it comes to car care, myths spread faster than engine oil on a garage floor. Some of these outdated tips might have made sense in the ’90s, but modern vehicles play by a different rulebook. If you’re still changing oil every 3,000 miles or warming up your engine for 10 minutes, it’s time for a tune-up, not of your car, but of your knowledge.

Let’s bust the most common car maintenance myths that are draining your wallet and doing your car no favours.

Myth 1: Change Your Oil Every 3,000 Miles

The Truth:
That rule might’ve worked for your dad’s old Corolla, but modern engines paired with synthetic oil can go 5,000 to 7,500 miles easily. Some high-performance engines even stretch to 15,000 miles. Your owner’s manual knows best.

Why It Matters:
Changing oil too frequently wastes money and resources. Unless you’re driving in extreme conditions daily, you can safely follow the manufacturer’s guidelines.

Myth 2: Warm Up the Engine Before Driving (Especially in Cold Weather)

The Truth:
Today’s engines are built to be driven almost immediately. Idling too long in the driveway can lead to incomplete combustion, more emissions, and wasted fuel.

Pro Tip:
Start the car, wait about 30 seconds, then drive gently. The car warms up faster while in motion.

Myth 3: Premium Fuel Boosts Performance

The Truth:
Unless your vehicle requires premium fuel (check the fuel door or manual), regular unleaded is just fine. Premium doesn’t mean “better”; it just has a higher octane rating, meant for engines with higher compression ratios.

What Happens If You Use It Anyway?
You’re just paying more at the pump with zero performance gain. In some cases, it might even lead to carbon buildup.

Myth 4: Only the Dealership Can Service Your Car Under Warranty

The Truth:
As long as you follow the recommended service schedule and use a qualified mechanic, your warranty remains intact. Just keep detailed records and receipts.

Why This Myth Persists:
Dealerships often use this as a sales tactic. Don’t fall for it.

Myth 5: Inflate Tires to the Maximum Pressure on the Sidewall

The Truth:
That number is the tire’s maximum capacity, not the ideal pressure. Always use the manufacturer’s recommended PSI, found on a sticker in the driver’s door jamb.

Real Risk:
Overinflated tires can reduce traction, increase wear, and affect braking performance.

Myth 6: Car Batteries Always Last 5 Years

The Truth:
Most batteries last between 3 to 5 years, depending on climate, driving habits, and electrical load. Hot weather tends to kill batteries faster than cold weather.

Tip:
Start testing your battery annually after year three.

Myth 7: Brake Fluid Never Needs Changing

The Truth:
Brake fluid is hygroscopic, meaning it absorbs moisture over time. This can lead to corrosion in the braking system.

Recommended Interval:
Every 2-3 years, unless your manual says otherwise.

Myth 8: Wait Until Tires Reach 2/32” Tread to Replace Them

The Truth:
That’s the legal minimum, not the safe minimum. Replace your tires when tread depth hits 4/32″ if you frequently drive in the rain. More tread = better grip.

Test It Yourself:
Use a quarter. If Washington’s head is covered, you’re above 4/32″.

Myth 9: Transmission Fluid Needs Flushing Every 30,000 Miles

The Truth:
Not always. Many modern cars have transmissions that don’t require service until 60,000 to 100,000 miles. Some are sealed for life.

Best Practice:
Check your manual before making assumptions or spending hundreds unnecessarily.

Myth 10: Replace the Engine Air Filter Every 12,000 Miles

The Truth:
Filters can last up to 30,000 miles, depending on your environment. Inspect them regularly and replace only when dirty or per your manual.

Why It Matters:
Unnecessary replacement = unnecessary cost. And no, a dirty air filter doesn’t boost horsepower.

Honorable Mentions: More Myths to Avoid

Coolant must be changed yearly: Not true. Some last up to 5 years or 150,000 miles.
Dish soap is fine for washing cars: Nope. It strips wax and damages paint. Use car-specific soap.
Rotate tires at every oil change: Most cars are fine rotating every 7,500 to 10,000 miles.

Real-World Impact

A 2024 AAA study revealed 45% of drivers still follow the outdated 3,000-mile oil change rule. Multiply that by cost and time wasted, and you see how harmful misinformation can be.

Online trends, especially on platforms like X (formerly Twitter), still circulate these myths. But credible sources like Consumer Reports, Access Roadside Assistance, and AAMCO have published clear, updated facts.