5 Car Myths Busted

Automotive myths are as common as a rainstorm after a carwash. Find out which are fiction and which could be breaking your bank.

car myths busted

Have you ever heard that adding sugar to your gas tank will destroy the car’s engine? Or that premium fuel will clean out your injectors? Did you know that both of these statements are false?

Unfortunately, automotive myths like these are as common as a rainstorm after a car wash, and some of them could cost you time and money if you’re not equipped with the truth. Here are 5 debunked car myths to scratch off your list.

Car myth #1: Red cars cost more to insure

We already addressed this one in the car insurance myths section of our website, but it’s worth reiterating here. There are 2 sides to this myth: The first is that brightly colored cars, especially red and yellow ones, cost more to insure. The second is that they’re more likely to get a ticket.

On the insurance end, this pans out to nothing more than a myth because insurance companies don’t take color into account. And even if they did, some studies suggest cars that are hard to see at night — black, navy, green — are at greater risk for accidents.

What about tickets? It makes sense that a cherry red coupe would draw more attention than a charcoal sedan, but according to Snopes, that myth was dispelled as far back as 1990.

Car myth #2: Warm your engine when it’s cold out

In Los Angeles, where I live, “cold out” means 50 degrees and cloudy. If you reside somewhere like the arctic wilds of New England, however, you might have a habit of letting the car idle for a few minutes to warm the engine.

But unless you drive an older car, you’re wasting your time by warming up your engine. (Tweet this.)

See, up until the ’80s, cars used a system of valves and chambers called a carburetor to control the mix of fuel and air being pumped into the engine. Back then, carburetors did have problems adjusting to cold temperatures. But modern car engines are now built with electronic fuel injection systems instead of carburetors, and these systems use an ECU (engine control unit) to detect oxygen levels, automatically adjusting the fuel-air ratio accordingly.

Another bonus: fuel injection systems also improve mileage and cut down on emissions.

Car myth #3: Premium gas gets better mileage

The only reason you’d ever want to pay more at the pump is because your owner’s manual specifically says that your car needs it.

The one real difference between regular and premium gas is in how long it takes to combust. Premium gas has a high octane level, which means it requires more pressure from the engine to do its job. In high-performance cars, low-octane gas can ignite too quickly. This is bad for the car and causes a loud noise called “engine knock.” In other words, a high-performance car demanding premium gas must use premium gas to avoid damaging the engine.

But premium gas makes no difference in a regular car, so don’t waste your money. (Tweet this.)

Car myth #4: Gang initiates are targeting people who flash their headlights

Okay, so maybe this isn’t as widespread or as practical as the previous automotive myths, but I honestly believed it for years and was relieved to learn it was nonsense.

The story goes something like this: a gang is initiating new members, telling them to drive around at night with their headlights off and kill the first person to flash high beams at them.

According to Snopes, this urban legend has been in circulation at least as far back as 1993. At the time, the rumor was pegged to a “blood initiation weekend” in late September. Several states were affected, from California to Texas to New York, but no incident ever actually occurred.

You may not have heard this particular car myth, but it’s important to include an example of scaremongering so you can know what to look for. That’s not to say you should discount anything that sounds suspicious, but at least do some research.

Car myth #5: Shooting the gas tank will cause a car to explode

If you’ve ever seen an action movie like Mission: Impossible or The Terminator, you’ve watched as the protagonist shoots a single bullet into a vehicle’s gas tank, causing it to explode.

The guys at MythBusters tackled this one in 2004 and again in 2005. And while they did admit that it could be possible to blow up a gas tank with a single tracer round (such as a flaming bullet) from a great distance, they also agreed that it’s extremely unlikely — and never a good idea.

Of course, car myths pop up every year. There’s bound to be a new generation of absurd anecdotes related to automated systems, smartphones, and sensors, but all it takes is a quick google search to set you free … and possibly save you money.

What are some of the other myths you’ve heard? Sound off in the comments section below.

Related links

Car seat myths abound, too. Get the facts.
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408 Responses to “5 Car Myths Busted”

  1. Rene medlin
    February 21, 2014 #

    I read an article a while back about the exploding gas tank a nd a cell phone. Seems that women are more likely to get in the car while filing up. Then when they get out of the car and grab the pump handle it creates a static electricity charge that could react (explosion) with the gas fumes from the tank.

    • Heidi Reckel
      March 11, 2014 #

      Again, disproven by Mythbusters. It takes a heck of a spark and way more than average amount of vaporizer gas to create the explosion. Seriously, go to http://www.discovery.com/mythbusters and look for this one. I'm sure it's on the site, since this is such a popular myth.

      • Robert Miller
        March 25, 2014 #

        Mythbusters don't get it right all of the time. I worked with an gasoline delivery driver who use to deliver gas to stations very early in the morning when the air was very still. The guy smoked and one morning after he lit up he noticed just a few inches above the ground a glow. He realized he had ignited the gasoline vapors, which are heavier than air and latterly the ground all over the station was on fire. (A vapor fire.) He shut of the valve on the tank and they went out. He then opened the valve and finished filling the tanks. When he got home he noticed the bottom of his trousers and socks were singed at the level of the vapor fire.

      • FrankOK
        April 7, 2014 #

        I saw that "Mythbusters" episode also and being on the left coast, they probably didn't have access to the proper ammunition since they're based on the left coast..

        Tracers are iffy in regards to setting off a gas tank. The ammo they should have used is designated as "APIT" – armor piercing incendiary tracer. Yes, it exists. It not only has AP capabilities and a burning trace compound in the base but also a small explosive charge in the forward part of the projo.

        The trick is using the hydraulic effect of the projo hitting the tank to disperse/mist the fuel as it WILL NOT BURN without oxygen. A second round hitting nearby can detonate the mist if not set off by the first. This is the principle behind the fuel/air bombs our military uses on Pampers™-wearing rats in caves to great effect.

      • John
        May 21, 2014 #

        Having had an empty metal tank "go off" while I was repairing a hole I can tell you that gas tanks do not explode the way they show in the movies. Gas need to be mixed with air at about 1 to 14 parts to burn. A full tank has very little air and will not explode. The tank I was working on bulged out but did not explode, just scared the *** out of me. It did move a bit from all the pressure going out the fill hole like a rocket engine.

  2. supershiftsuper
    February 25, 2014 #

    In cold weather, engines should be let to idle for a minute or two to let the oil get pumped up to the cylinders etc. Cold weather thickens oil, and impedes it's flow.

    • jaylon willion
      March 2, 2014 #

      Pumped up to the cylinders? If you're pumping oil to the cylinders, overhaul the engine. Pump oil to the bearings and lifters, yes. Cylinders, no.

      • Chaser Eraser
        March 4, 2014 #

        Always allow you vehicle to warm up in cold weather – at least a few minutes – higher rpm operation with cold motor oil can wear the internals of the motor more quickly – (scoring of cylinder walls, etc) Once warmer oil is circulating through the engine you can be sure that operating at higher Rpms will not cause unnecessary wear on the motor. Also, the oxygen sensors don't adjust fuel trim until the vehicle is warm – the vehicle will operate in warm up mode – "open loop" ignoring oxygen sensor input until a predetermined temperature. You don't need a 1/2 hour idling in the driveway – a few mins will do. Because operating the engine at higher speeds (driving down the road to work or school) will put the vehicle in "closed loop" where oxygen sensors are watched and fuel economy is improved.

      • L.J.
        March 6, 2014 #

        Then why is the bottom piston ring an "oil" ring? It wipes the oil from the cylinders. No oil, ruined pistons and cylinders. Thinking or knowing before you speak would help!

      • John
        March 19, 2014 #

        Yes Jaylon, pumped into the cylinders. Oil provides the lubricant necessary to reduce/prevent wear between the piston rings and the cylinder walls. Seizure of the oil scraper ring, the uppermost of the piston rings, will result in significant but harmless oil consumption. Unless of course you do not add oil as necessary.

      • darrell
        April 5, 2014 #

        Oil does go to cylinder.. to keep pistons from getting hot and expanding in cylinder ..if no oil then engine will seize up and u need a new engine..

      • Billy Joe Jim Bob
        April 5, 2014 #

        Lifters? Must be driving an antique…

      • David Thomure
        April 23, 2014 #

        Yes cylinders. As the piston goes up the cylinder, oil follows. The Rings Keep The Oil Out Of The Combustion chamber. Without oil on the cylinders with each stroke your engine won't last long.

      • Racer
        May 16, 2014 #

        Myth two is bogus. It is different in Florida and Arizona from Wisconsin, Minnesota, Montana. There is a good reason to warm up. Like John and Darrell said there is a reason oil is there – lubrication! When it's 0* oil is like sludge. Carbs vs injection has nothing to do with it. Modern injection engines are fine, but the turbos, no, they need warm oil to survive. I know having worked on jet aircraft and now build race engines. Oil needs to be warm to properly lube lifters, pushrods and cam – and turbos that spin up to 40,000 rpm. And a properly adjusted oil ring will allow the right amount of oil to the cylinder walls – extending engine life! Right on LJ.

      • Rem
        June 3, 2014 #

        Haha, you're a great mechanic bro. Must have used Wikipedia to learn how.

      • Bill Tyree
        June 15, 2014 #

        Through the pump, gallery, main bearings, rod bearings, wrist pins, cylinder walls and rings. Yup, cylinders. And the oil in the engine has had all night to drain down off the cylinder walls.

      • Bill Tyree
        June 15, 2014 #

        And oil doesn't just lubricate an engine, it carries away excess heat from the cylinder walls and pistons.

    • Greg
      March 20, 2014 #

      Low temperatures thickens petroleum based "mineral" oil. I use synthetic oil which is not affected by extreme cold temperarures.

    • Billy Joe Jim Bob
      April 5, 2014 #

      Again, you don't know what you're talking about. You must be an old wife, because this in an old wive's tale.

    • Tammy
      May 17, 2014 #

      I'm glad to see this comment on here. I was going to post it but I thought I'd look to see if it was already here. Good to know I'm not the only one thinking this way.

    • CPaulUU
      June 18, 2014 #

      At idle, the pistons are going up and down 10 times per second. There is enough residual oil on the cylinder walls to handle this or else engines would wear out very quickly even if warmed up. At driving speed this doubles to twenty. No big deal. Warming up is a waste of gas.

    • Jack Hammer
      June 24, 2014 #

      Well done. Oil circulation is the main reason you should never turn the key and go. I let the engine idle for ten seconds or so even on a warm engine. GThe other reason is what they call Engine operating temperature. The engine Parts don't fit right Until they reach Optimum temperature. Old engines Will burn some oil out the tail pipe until the pistons and rings expand in the cylinders Especially if you run them hard when cold. ,
      A good rule is take it easy on the engine for the first couple of minutes until the cold light goes out out you see temperature on the gauge.

      If a warm up is good for race car and airplane engines it's good for yours.

    • George
      July 10, 2014 #

      number two is incorrect,,, ALL engines should be at or close to operating temps especially in cold weather. this allows for all critical engine clearances to stabilize and be in a correct operating dimension to avoid damage,, example,, pistons made of aluminum expand quickly under a load I.E driving conditions and if the cylinder walls and coolant in the engine block are cold the block usually made of cast iron, will expands slower than the piston causing a piston to cylinder wall tightness that cases "cold scuffing" or in extreme cases "cold seize" not to mention cold oil is harder to pump causing more fatigue on the oil pump drive components resulting in premature failure,, Always allow warm uip in cold weather,,, fuel injection just makes cold driving easier as far as engine staying running with a proper stoich,,,, the colder the temp the more warm up time,, basic engine operation 101 since the advent of piston engines

    • James McGinn
      July 20, 2014 #

      The newest engines use oil like 0w-20 and with oil that thin I don't think this is necessary either. Pull away gradually soon as the engine starts. Besides hybrid engines on many vehicles like PHEW's don't even start at all until needed, several miles from home.

    • Bob
      October 20, 2014 #

      NOT true. Higher valve spring pressures exist at idle speeds – essentially creating more wear waste of gas, get in and drive it easy… 5/30 oil still flows cold

  3. vtxssy
    February 26, 2014 #

    Also letting a car warm up helps transmission shift properly in cold weather. Lots of cars out there don't shift like normal in cold weather.

    • 1rockola
      March 4, 2014 #

      vtxssy is correct. In extremely cold weather (polar vortex) fluids need some TLC in order to circulate and do their job. Every car I have ever owned (I've been driving for over 50 years) the Trans. needed time to adjust and if not given the time would shift with a "bang". Treat your vehicle nice and most of the time it will treat you nice.

    • Billy Joe Jim Bob
      April 5, 2014 #

      More like an excuse for you to waste precious natural resources. That's okay, neither one of us will likely see the end of oil before we die. Why not be wasteful?

      • Jason
        June 23, 2014 #

        Absolutely. It's a horrible waste to let my vehicles warm up for 3-5 minutes. But you know what. That $70000 worth of vehicles in my garage and drive were damn well hard enough to come by to be worth taking care of. My vehicles are from 11 to 3 years old. They were purchased new and well maintained. They will all last another 10 years or better and they'll get warmed up almost every time they're started. It gives them a minute to get their fluids pumping and delicate parts to operating temperature. It also helps the defrost on the windows and the temperature in the passenger cabin. While this is going on I make a lap around the vehicle to see nothing is behind or under it and the tires, wheels, and lug nuts look good. Then I get in and wait for the wife and kid as they tend to always be 60-90 secs behind me. When we pull out to leave the engine is almost at operating temp, the heat/defogger/defrost is at operating temp, windows are clear and wife has nice cool or warm passenger seat.
        Now, I'm all for the environment. And a happy wife does ALOT for one's environment!

    • Ron
      April 9, 2014 #

      Yes you don't need to warm your car in LA. But in WI you do. If engine is cold, and below 10° your windshield will frost up from your breathing.
      Also good to thin oil out.

  4. Heather
    February 27, 2014 #

    Its against the law to let your car idle unattened in Colorado. And with fuel injection the only reason to idle your car would be to defrost and warm the interior.

    • George
      March 1, 2014 #

      It's against the law to leave the keys in the ignition and car unattended. Remote start on the other hand would be fine, as the vehicle remains locked.

  5. me
    February 27, 2014 #

    5 car myths busted. You are fulll of it. If you don't think sugar will gum up your engine, pour some in your tank and drive it for a few days. I personally know it will turn to gummy syrup and eventually hard black crud. It will seize the engine or cause the valves to stick open which will cause big problems. Find an old lawn mower and try it. Same goes for old gas.

  6. CCA2011
    March 1, 2014 #

    Something else not stated is that in colder temps oil is thicker than usual so warming up the car helps thin the oil out. Now where that is useful is the fact that if you do not let the engine warm it works harder to push the oil through the engine. Over time that over working causes wear and tear on the pistons, cylinder walls and in some cases will even cause head gaskets to leak which will allow large amounts of oil out of the engine and cause it to fail. Now that is an extreme case but it can and has happened. So better safe than sorry on this

    • Billy Joe Jim Bob
      April 5, 2014 #

      More old wive's engineering. Most people run synthetic oil, and those in colder temps use a multi-viscosity formulation, which is formulated specifically to combat these problems.

  7. Ellen Hall
    March 3, 2014 #

    We appreciate your comments – thanks for making this such a lively discussion. But please remember to keep the dialogue civil. Comments which include name-calling or personal attacks will not be published.

  8. Ian
    March 5, 2014 #

    Are you all brain dead? Most people warm their cars up for the simple fact that they don't want to drive an ice cold car and shiver the whole way to wherever they are going. It's not about the engine or oil or whatever.

  9. randll
    March 5, 2014 #

    Went to car talk page. They say no more than a minute or two for idling then drive the car. So in this case, at least one of these myths are incorrect. So nice going.

  10. Don Mace
    March 8, 2014 #

    Ok I understand why not to leave your car idle for more that 2 minutes, but I live in Iowa it has been COLD the entire winter. I don't like going out and starting my car let it idle for 2 minutes and then driving of with an interior temp of -10 sorry, I always let my car run for 20 minutes in frigid temps just to warm up the car to at least 32 above zero!

    • Billy Joe Jim Bob
      April 5, 2014 #

      Thanks for wasting precious natural resources.

      • Dave
        April 22, 2014 #

        Billy Joe Jim Bob,
        Are you hugging a tree while typing this response?

      • Lone Star
        June 21, 2014 #

        I live in texas we let the car Idle for 10 or 15 min. just to cool it off so we can touch the steering wheel ! LOL

      • Jeff DeWitt
        June 23, 2014 #

        In really cold weather I'll do the same thing. Not only does it make the car more comfortable but the defroster work better. If it also annoys a greenie that's just an added bonus.

      • Jane
        June 30, 2014 #

        The convenience of heating up the car for 10 minutes on a cold winter morning is just what I need!

  11. Frank
    March 8, 2014 #

    Warming your car up in cold weather saves wear on your engine. From my motorcross days I remember that a cold engine has more horsepower than a warm engine because of the tightness of cylinders… a warm engine allowed expansion of the cylinders and gave less compression. I got many hole shots by starting my engine at the last minute. In any case, the tighter the cylinder the more wear on the rings. My rings wore out faster but gave me an advantage.

    • Dave
      March 14, 2014 #

      You can accomplish the same thing by driving the car at high idle— not hitting the gas for a while. If you can get away with driving 20-30 mph for the first two minutes in your trip

    • Pat Kittle
      June 15, 2014 #

      The real reason your cold engine had more horsepower is because colder air is denser, so you had slightly more air-fuel mixture entering the engine before it heated up. This is especially true if your motocrosser had an air-cooled engine, whose intake tract (& of course exhaust tract) typically get hotter (which is why liquid-cooling was adopted decades ago).

      BTW, piston ring-gap decreases in a warm engine, which increases effective compression.

      • Todd C.
        July 7, 2014 #

        Nice Pat. I think you are the only one that mentioned anything about thermal expansion of the pistons and rings to the cylinder walls. Yes, machining tolerances have changes a lot in the years and so have the metals being used, but you can not get past the laws of physics. If you have an aluminum piston and cast iron block (like most engines do) then you need to let the engine warm up a little before you have the best volumetric efficiency. I'm not saying that you have to let it run for more then a minute. Drive the car after it has been started, but do not put a heavy load on it. Give the pistons time to expand before you drag race that Porsche next to you at the stop light. This is especially true if you have a turbo charged car. Let your engine coolant get to operating temperature before you try to get full boost. Also, let your turbo cool down before you shut it off. When i worked at a new car dealer I replaced many engines because the oil was coking up in the turbo.If it did not take out the bearings in the turbo, it would cause flakes to fall into oil pan and plug up the oil pick up. And yes, even the owners that put the good synthetic oils in had the same problem if they did not let the turbo cool down before turning off the engine. Try driving up a long hill and then open the hood and look at your turbo, it will be glowing red.

        Cold running engines have a higher Hydrocarbon (HC) output and the catalytic converter is not warm enough to deal with it yet. The auto makers added a Secondary Air Injection System (AIR) to help warm up the catalytic converter, but it still does not take effect until the car has been running for at least a minute. Most times you can hear the AIR system running. It sounds like a hair dryer under the hood. Driving the vehicle at light throttle will help warm the cat and help the emissions.

  12. bryan moore
    April 12, 2014 #

    Im freezing. Foget that. Im going back in the house, let this car warm up 1st.

  13. Fleendar the Magnificent
    May 6, 2014 #

    Here in the cold north, we warm our cars up so that the snow and ice melt off the windshield so we can see out of said windshield. We also like getting into cars that aren't -10 below zero.

    • fran666b
      August 26, 2014 #

      here in canada it gets to -40 in the coldest month of winter

  14. Valerie Lewis
    May 17, 2014 #

    I drive a fifteen year old Dodge Ram 1500 4×4. When I lived in California I didnt need to warm up my truck in winter. But now that I live in South East Texas I do have to warm my truck or it takes its time shifting gears. The cold here is more intense. And I use synthetic oil. I take good care of my truck. And it takes care of me.

  15. RJ Muhlheim
    May 17, 2014 #

    Start our car. Let it idle for 20-30 seconds. Drive it gently for 2 miles or 2 minutes. It will last much longer. Lubricants work better when they are warm. A modern auto is full of bearings, gears, and surfaces that rub on each other in the engine, transmission, axels, brakes, alternator, power steering, air conditioning, suspension… all have systems to provide lubrication. Allow them to function in a lowly stressed manner to help their lubricants move to places it is needed. Most of the wear that happens in auto engines occurs during cold starts and short drives. Try to drive your car until the temp gauge comes up to temp for a few minutes or until the defroster or heater give good hot air flow.
    Combustion produces water and/or vapor which mixes with gasses from sulfur that is in motor fuels forming acids that erode light metal parts of engines… bearings, pistons, metallic gaskets, cast aluminum parts in some water pumps, manifolds, cylinder heads and engine blocks. Complete warm up every drive cycle drives off the water reducing the acid forming corrosion problems and greatly extends the life of engine oil and extends the life of any engine.

  16. Gunnar C
    June 15, 2014 #

    I lived in Alaska for 6 years. This guy is talking nonsense about getting in and driving away. In cold climates you must let it warm up so the fluid can circulate properly. If you want accurate automotive advice don't get it from Yahoo… see an ASE certified mechanic.

    • fran666b
      August 26, 2014 #

      yes sir I live in northern Ontario in Canada and when it get to -40 the oil and fluids are thick like mollasses its aviously not good for the engine

  17. Pat Kittle
    June 15, 2014 #

    (Regarding myth #3):

    You promote another myth as you bust this one.

    Premium gas does NOT "…REQUIRE[s] more pressure from the engine to do its job."

    It DOES ACCEPT more pressure.

  18. CPaulUU
    June 18, 2014 #

    Many modern engines have a computer that senses knocking and detunes the higher performance engines to eliminate it. They won't perform as well during acceleration but thats the only disadvantage. It's rare to hear an engine knock any more. An exception to this is engines with superchargers or turbochargers. They need premium.

    What's worse is that it doesn't cost the oil companies much more to produce premium. Gasoline is a blend of aromatic hydrocarbons and no two batches have the same composition. They are mixed to provide the desired 'octane rating'. Premium may have an additive keeping it from igniting under compression. The name is a misnomer. As you pointed out its harder to ignite and should be called low-grade gas. Its all marketing.

  19. Thomas Robson
    July 24, 2014 #

    This made me smile, there are still so many people who believe these myths! Particularly number two- I’ve lost count of the number of times I’ve seen people sitting in their cars in the driveways waiting for their engines to get a good warm through!

    • fran666b
      August 26, 2014 #

      it gets to -40c here in winter and the oil is thick like molasses dont tell me its good for the

  20. Eric
    August 2, 2014 #

    Pretty sure my insurance company and others definitely do charge more for a bright colored car; red especially. Also its certainly better for the engine to have time to warmup on a cold day.

  21. Simcostan
    August 6, 2014 #

    Well i drive a 2.6l mitsubishi colt, leather interior so in the morning it **c* cold bt i just turn key, reverse, put 1st gear an accelerate an it drives as if iv'e been driving all day, all this heating an lubricants don't sense to me.

  22. PD Plotnick
    September 28, 2014 #

    Everyone is right. And wrong about warmup. We can all agree that warm oil does a better job of lubricating and that the sooner the engine reaches operating temperature, the better. An engine will warm up faster under light load than idling. Hence driving it slowly – but driving the car – makes more sense than letting it sit there idling and wasting gas. If you want warm seats, that's another story – but you can buy a car with heated seats. I had an Audi that had 'em and I loved it. My'02 Accord does not.

  23. t
    October 1, 2014 #

    Warming up the car for defrost reasons is a safety standpoint. Doesn't metal contract when cold? I.E. piston shrinks and sleeve diameter actually increases. (Ever frozen a ball joint before installing it?). Now you need less lubricant. Granted, pushing thickened oil through an already slugged/clogged pickup tube or filter etc. could cause an over oil pressure situation and turn a small leak into a larger one, or take out the oil pump or force a new leak from a weak point. All things considered, I will at least warm my car up to 1/2 operating temp, or to where my defrost works.

  24. I'm right
    October 6, 2014 #

    Actually warming up the car for defrost reasons is not a safety standpoint. Metal doesn't contract when cold. I.E. Water expands when it is frozen, and as does metal. Now you need more lubricant. Granted, pushing thickened oil through an already slugged/clogged pickup tube or filter etc. could cause an over oil pressure situation and turn a small leak into a larger one, or take out the oil pump to force a new leak from a strong point. All things considered, I will not at least warm my car up to 1/2 operating temp, or to where my defrost works.

  25. Jono Campoli
    October 22, 2014 #

    #2 is true. Premium fuel gets better mileage because it doesn't have Ethanol in it. Ethanol burns much quicker.

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