Do Not Fall For These 15 Car Myths

Car owners often fall for misleading myths lacking scientific backing, hindering vehicle performance and longevity. Despite some truths, most myths are too good to be true, with facts often obscured. Persistent misconceptions about car maintenance and driving, like oil change intervals and self-driving cars, require debunking to prevent potential harm and costly repairs. It's time to uncover the truth. Skim through to discover 15 common car myths that could harm your vehicle and wallet.

Truth - Modern vehicles do not require extended idling before driving in cold weather. Idling for more than 30 seconds wastes fuel, generates emissions, and can potentially harm the engine. The most efficient way to warm up your car is to start driving gently, as today's engines are designed to warm up quickly and efficiently even in cold weather. Warming up the car for the time it takes to clear and defrost the windows is sufficient. This misconception may have originated from the time when cars used carburetors, which required extended idling to ensure proper engine function. However, modern vehicles use fuel injection systems, which do not have the same requirement.

Truth - To optimize fuel economy and reduce emissions, modern vehicles with fuel-injected engines should not be left idling for extended periods. Instead, start the engine and begin driving gently to allow the engine and transmission to warm up evenly. This practice is more efficient than idling the engine and reduces fuel consumption and emissions. The misconception that extended warm-up times are necessary may have originated from the time when cars used carburetors, which did require extended idling. However, modern vehicles use fuel injection systems, which do not have the same requirement. Many modern cars have an automatic engine shut-off feature that turns off the engine when the vehicle stops and starts it back up again when the gas pedal is pressed to save fuel and reduce exhaust emissions.

Truth - The misconception that regular fuel harms performance engines or that premium fuel enhances performance in non-premium cars is unfounded. The key difference between regular and premium gas lies in their octane ratings. Premium gas has a higher octane rating, igniting at higher pressures and temperatures than lower octane fuel. It is crucial to adhere to the manufacturer's fuel type requirements specified in the vehicle manual or near the gas tank cap. If the manufacturer mandates the use of premium fuel, it is essential to follow this requirement strictly. However, if premium fuel is recommended but not mandatory, using regular fuel is generally acceptable. While using regular fuel may result in slightly lower horsepower or fuel economy compared to premium fuel, it does not harm the engine or its longevity. Numerous studies indicate that the performance gap between premium and regular fuel is minimal, with limited real-world benefits. 

Truth - Modern automatic transmissions have higher gear ratios and some even have infinite gear ratios, like continuously variable transmissions, which can lead to better fuel efficiency than manual transmissions. Newer automatic models can have better mileage according to EPA ratings compared to their manual counterparts. This misconception may have been true in the past, but modern automatic transmissions have evolved to be more fuel-efficient than manual transmissions.

Truth - Using the air conditioning (AC) in a modern car does burn more fuel than not using it. However, the impact on fuel efficiency can vary depending on factors like driving speed, outside temperature, the condition of the AC system, driving habits, and the type of vehicle. Generally, at highway speeds, it is more fuel-efficient to have the AC on than to drive with the windows down due to the aerodynamic drag caused by open windows. The effect of the AC on fuel consumption can range from 3% to 10% or more in severe conditions. While driving without the AC may save a small amount of gas, the comfort provided by the AC often outweighs the minimal increase in fuel consumption. Additionally, factors like the size of the vehicle and driving conditions play a role in how much fuel is consumed when the AC is used. If you do notice issues with the system, here's how you can diagnose your AC compressor.

Truth - The myth that filling your gas tank in the morning saves you money by getting denser gas due to cooler temperatures is not entirely true. While gas density changes with temperature, the difference is minimal regardless of the time of day due to gas being stored in underground tanks. Gas stations often have mechanisms to compensate for temperature changes, ensuring you receive the same amount of fuel regardless of when you fill up. Therefore, making a special trip to fill up early in the morning is unlikely to save you money in the long run.

Truth - The myth that adding special additives to engine oil can increase engine performance, reduce fuel consumption, or make the engine last longer is not entirely accurate. Engine oils are specifically formulated to provide optimal lubrication, protect engine components, and enhance performance. While additives may offer some benefits, they are unlikely to significantly improve fuel efficiency or engine lifespan beyond what the manufacturer's recommended oil provides. Research is essential to ensure compatibility with the engine and the manufacturer's recommended oil, as some additives may not be suitable for certain engines or conditions and could potentially cause harm or void warranties.

Truth - A higher (thicker) oil viscosity is not always better for an engine, especially in modern engines with tight tolerances and sophisticated technology like variable valve timing that relies on precise oil pressure for proper functioning. Using thicker oil than recommended can lead to engine damage, as it may not flow into tighter orifices during cold starts, causing increased wear and tear. However, thicker oils may be suitable for older engines with high mileage, as they can provide greater lubrication levels and offer enhanced engine preservation. It is essential to follow the OEM recommendations for engine oil type and grade, as using the incorrect engine oil type can cause various kinds of damage to the engine and harm its functionality over time. The viscosity of the oil is critical, as it keeps metal parts separated within the engine, and the proper viscosity grade does that. However, using an oil that is too thick creates too much frictional drag within the oil itself, which generates extra heat and can rob engine performance by reducing horsepower.

Truth - Unless you have an extremely old vehicle (30+ yo) with a high-mileage engine, you do not need to replace the oil every 5000 km. Most modern cars can go without an oil change for up to 15,000 km. The oil change interval depends on many factors such as the vehicle, driving condition, location, and the type of oil used. Conventional oil needs to be replaced at about 8000 to 10,000 km. Synthetic oils can last longer than conventional oils and so have longer replacement intervals. Semi-synthetic or synthetic blends and fully-synthetic oils have change intervals ranging from 12,000 to 15,000 km. This number can be extended even further if you are only driving on highways. This is because highway driving does not deteriorate engine oil as much as stop-and-go traffic common to city driving. 

However, you need to change the oil every year regardless of the mileage because the oil breaks down over time and so needs to be replaced, especially organic oils. Also, it is recommended to replace the engine oil filter during every oil change.

Truth - The myth that you can adjust tire pressure to suit driving conditions is not entirely accurate. For regular driving and highway commuting, it's recommended to stick to the manufacturer's tire pressure specifications. Under-inflating tires to improve ride comfort or over inflating for better fuel economy can lead to increased tire wear, fuel consumption, reduced safety, and handling performance. The only exceptions are off-roading on sand or rocky terrain, where under-inflating the tire can provide better traction, and driving in extremely cold weather, where slightly over-inflating can compensate for pressure drops due to temperature changes. However, it's essential to maintain the recommended tire pressure to ensure optimal tire life, handling, fuel efficiency, and most importantly your safety.

Truth - The myth that transmission fluid labeled as "lifetime" does not require replacement is false. While the term "lifetime" typically refers to the vehicle's lifetime, it does not mean the fluid lasts forever. Manufacturers may not suggest a transmission fluid change interval in their owner or service manuals, but regular fluid changes are still necessary for long-term reliability. Transmission fluid and filters can become contaminated with metallic particles and deteriorate over time, leading to expensive repairs if not addressed. It is recommended to change transmission fluid and filters every 30,000 to 60,000 miles, especially for vehicles with high mileage or those experiencing shifting problems.

Truth - The myth that changing automatic transmission fluid (ATF) in high-mileage vehicles can cause transmission issues is debated. Some argue that changing the fluid in older vehicles could lead to slipping or failure, especially in neglected cars with high mileage and never-changed ATF. This is because the gritty fluid is seen as providing needed friction for worn internal components. However, others emphasize the importance of regular maintenance and fluid changes to improve transmission performance and longevity. Fresh ATF provides essential qualities like anti-corrosion, lubrication, and cleaning agents. The decision to change ATF in a high-mileage vehicle should consider the vehicle's maintenance history, the condition of the transmission, and expert advice. Regular maintenance and following manufacturer recommendations can help ensure the longevity and performance of the transmission.  Here are some of the other essential fluids in your car that need to be replaced regularly.

Truth - Many products in the market claim to increase the fuel economy or engine performance or both by either adding a bolt-on part to your car or through some electronic gadget you can install. You might have seen ads on late-night TV that feature paid testimonials that make you think they actually work. The truth is that all such components are a big rip-off designed to take your money and nothing else. Some even provide scientific reasoning behind their madness to justify the expense but they are just marketing tactics and have no real-world benefits. If such technologies did exist, the manufacturers would be intent on adding them to the vehicle to make their vehicles greener instead of spending billions on research to reduce emissions and increase fuel economy. Modern engines are already as fuel-efficient as can be, so we insist you stay away from such fiction. For example, magnetic fuel senders, USB fuel-saving devices, etc. If you want actual products that increase engine performance and fuel economy you refer to this article on easy-to-do and affordable engine upgrades.

Truth - Older engines with more than 300,000 km that have not been cleaned or refurbished have a lot of carbon build-up. This build-up can reduce the combustion chamber clearance volume and increase the compression ratio. If you were to use regular fuel, there is a likelihood of knock or pre-ignition which if sustained over long periods can damage your engine. So engines with very high mileage can benefit from high-octane or premium fuel. As this fuel is less volatile, it can prevent knocking and therefore benefit the engine in the long run. You may also notice a slight increase in fuel economy since the engine runs better. However, you could clean up the engine and remove the carbon buildup or continue using premium fuel, as the difference in the long run is going to be the same and you may even get better fuel economy.

Truth - There is no evidence of mobile phones igniting gasoline fumes or causing fires at gas stations. The real danger lies in static electricity, not cell phones, as gas vapors around the pump nozzle can be ignited by static electricity, leading to potential fires. Therefore, while using a cell phone at a gas station won't cause an explosion, it is still advisable to be cautious of static electricity and avoid using your phone while refueling to prevent any risks.

Debunking car myths is crucial for saving money, preventing unnecessary maintenance, and ensuring safety. By understanding the facts behind these myths, you can make informed decisions about car maintenance and driving practices. Refrain from falling for common misconceptions. Stay informed and make decisions based on reliable sources. Remember, always consult your vehicle's manual and trusted automotive professionals for accurate information. Don't fall for these myths—drive safely and enjoy your ride with confidence!