Top 10 automotive myths

[fadi khan]

Throughout history all societies have embraced beliefs that eventually proved to be untrue, and the Internet has enabled the spread of myths of all kinds. Some of these “beliefs” involve the automobile; it’s time to separate the facts from fiction. Take a look at these popular myths, listed in no particular order. I’ve saved my favorite for last.

10. Myth: There is a federal law giving you a 72-hour cooling off period after buying a vehicle.

Reality: There is no such law governing vehicle purchases. The 72-hour rule only pertains to consumer purchases, in-home sales contracts, etc. Lobbyists (chiefly the National Automobile Dealers Association) killed the automotive provision at the time the law was being written. Dealers are allowed to voluntarily offer cooling-off periods but these are very uncommon and usually filled with disclaimers.

9. Myth: Premium fuel is much better for engines and produces more power.

Reality: Premium fuel only produces more power when used in engines that have higher compression ratios or are turbocharged or supercharged, or are otherwise tweaked for high performance. It actually burns less easily than regular fuel, so using it in an engine designed for lower octane fuel produces less power and yields fewer miles per gallon. Premium fuel also generates greater profits for the oil companies and that’s why you never see them advertise regular or mid grades.

8. Myth: Octane isn’t as high as it used to be.

Truth: Octane content is basically the same as it always was, but the numbers are lower. That’s because there are two methods of measuring octane level: Motor and Research. Gasoline used to be rated solely by the Research method, which yielded higher numbers than the Motor method. Today’s fuels use an average of the two and are therefore numerically lower. 100 Research (RON – Research Octane Number) is 94 octane in today’s rating system.

7. Myth: Engine oil should be changed every 3000 miles.

Reality: The last time engines required oil changes as frequently as every 3000 miles was in the mid 1960s, except for turbocharged cars in the 80s. Unleaded fuels and clean-burning engines of today require fewer oil changes, typically on the order of 7000-10,000 miles. Consult your owners’ manual and trust the engineers who designed the engines, not the fast-lube industry marketing folks who advocate 3000-mile changes.

6. Myth: Aftermarket oil and fuel additives work well and are worth the money.Reality: No, they don’t work well, and they’re not worth the money. TV and magazine ads demonstrating dramatic results fail to mention that the conditions shown in the ads don’t exist in every-day engine operation. Additives generally do nothing, although sometimes they can actually cause harm. If these relatively cheap compounds could truly, repeatably produce greater mileage and longer engine life, the auto manufacturers wouldn’t be spending billions on research and engineering to get small improvements out of their engines.

5. Myth: Putting sugar in the gas tank will ruin the engine.

Reality: Sugar doesn’t dissolve in gasoline nor does it mix if added as a liquid. It simply sits at the bottom of the gas tank. If sufficient amounts were introduced to reach the fuel pump intake, sugar could eventually clog the fuel lines or filters, thus stopping the engine but it could relatively easily be removed by blowing out the lines with compressed air.

4. Myth: Putting a potato into the exhaust pipe will stop the engine.

Reality: A potato pressed into the exhaust pipe will shoot out when the engine starts running.

3. Myth: The 200 MPG carburetor.

Truth: Many have heard this story in one form or another. It seems a neighbor of a friend of a friend knew of a man who bought a new car (variations of the story range from the 1940s to the 1970s). Shortly after taking delivery, he noticed that the car was getting fantastic gas mileage (some stories say 50 mpg, some say as much as 200 mpg!). His fuel gauge didn’t move from the full mark until he’d traveled many miles, so he opened the hood to see if something might be wrong with his gauge wiring.

What he saw after removing the air filter was a strange-looking carburetor. In fact, it didn’t look like a carburetor at all, but rather like a "black box." He kept driving the car for a few months and found he continued to get fantastic, unheard-of mileage. As the story goes, he was eventually contacted by a factory representative who showed up at his house and explained that an experimental carburetor was inadvertently installed in a production car and sold to him, but the factory wanted it back. Discussions ensued, with the result that the owner of the car got a top-of-the-line car in trade, plus some cash as long as he signed a non-disclosure agreement.

This story never happened and no manufacturer or private inventor ever developed a carburetor that would work in an automobile, although a few designs could be made very efficient on test benches in ideal laboratory conditions. If a super-efficient carburetor could’ve been developed, it would’ve been. Engineers wouldn’t have moved to sophisticated electronic fuel injection and engine management systems if they could have accomplished the same thing with a carburetor. Automakers wouldn’t be working so hard today to increase mileage if there were a simple solution to achieving it. Weight savings, sophisticated cylinder firing systems, hybrid drivetrains, etc., all exist to squeeze every tenth of a mile they can out of a gallon of gas.


2. Myth: The proper tire pressure is stamped on the sidewall.Truth: The pressure stamped on a tire’s sidewall is the tire manufacturer’s maximum inflation level for safe driving in all conditions. It’s not the “normal” inflation pressure and would be too high for every-day driving. The correct pressure can be found on a tag either in the doorframe area or glove compartment lid in your vehicle. The pressure is determined by many factors, including the vehicle’s weight, load-carrying capacity, operating parameters, fuel economy and speed potential. Tire and auto manufacturer’s engineers work very closely to arrive at optimum pressure levels for overall conditions and maximum tire lifetime.

And, last but by no means least, my favorite myth:

1. Myth: Ralph Nader killed the Corvair.

Truth: The Corvair was vilified by Nader as a death trap in his 1965 book, Unsafe At Any Speed, but GM had already made the decision to cease further development on the car one year earlier. The reason was the Mustang. In 1964, GM executives realized that the sporty, easy-to-option Mustang presented a competitive challenge impossible to overcome by the Corvair and its rear-engined configuration. Nader had no influence on the Corvair decision although he’s taken credit for it ever since.