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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450 Responses to “5 Car Myths Busted”

  1. mulissi
    July 4, 2013 #

    I've never heard that warming the car had anything to do with fuel and air. I've always heard it was to let the oil warm up so that it would flow and coat evenly, given the viscous properties of all liquids relative to temperature.

  2. Brian
    July 5, 2013 #

    I listen to Car Talk, and like many others they suggest warming the car to aid in oil flow. I will definitely take the advice of two MIT grads over a poorly written article, any day.

  3. thomas
    July 6, 2013 #

    The human eye recognizes red slower than any other color. That's why people believe that red vehicles are a higher risk to insurace companies.

  4. NIck
    July 7, 2013 #

    Flashlight Issue – You are 100% wrong on this issue. In the late 90's, I was driving with a friend at about 1 am when we spotted a car without its lights in the middle of the street. As we drove up to them and around, I flashed my beams so I could see better. The car was about 200 yards away from my friend's house where I was to drop him off. As I pulled up drop off my friend, I heard gunshots. They fired 3 shots at him and another 3 at me.

    Be very careful of the false sense of security you are providing people with this blog – you should really be more responsible with you information. This is 100% gang members who were out looking for random victims.

  5. Michelle Samano
    July 8, 2013 #

    I think you should do more research on your 5 myths to bust before you post again. If you put sugar in an engine, it will most definitely mess it up. And it will cost you money. In some states flashing your lights, is illegal. And insurance companies may not use the color of your car to determine your rate, but if you get pulled over and ticketed more often in one car compared to other, your rate is going to go up. You need to educate yourself.

  6. Harley
    July 10, 2013 #

    I am the owner of a high performance diesel engine building shop. I can assure you that all engines need to be warmed up at least some, and for sure, high quality engines. In addition to the oil thinning down to properly lubricate, there is also the factor of bearing tolerance, metal expands as it gets warmer thus changing the oil lubrication gap in the bearing and wear surfaces. Revving a cold engine is very hard on it and will cause excessive wear. That being said, many car manufacturers are taking this into consideration and increasing bearing tolerance on mass produced cheaper cars, because it is easier than educating the people. Use some common sense, even people need to warm up and flex a bit before a hard workout!

  7. Deskboy
    July 12, 2013 #

    Here is sunny south Florida, I start the engine to run the air conditioning so the car will be cool when I get in it. Even though I park it in the garage, the garage does not have a/c. It really gets hot in there. Sometimes when I get in the car, it so comfortable, I take a little nap before I open the garage door. It is my favorite part of the day.

  8. slamdunksonyou
    July 12, 2013 #

    esurance & anthony larsen,

    please do not give advice regarding subjects you are ignorant of. it is imperative to refrain from spreading mis-information when advising for the safe operation of heavy machinery such as automobiles.

    i will help you understand.
    #2 is true. engine oil does not lubricate well at room temperature.
    and #3 is also true. more efficient combustion creates more power, subsequently requiring less throttle thus consequently and effectively burning less fuel to travel the same distance.

    as a result of this proper lesson you are now smarter and you are welcome.

    i wish you luck because if this blog is any evidence of your proficiency you are going to need lots of it.

  9. Rick Sturm
    July 17, 2013 #

    If someone else said this, I missed it. I think I was driving a car built in the sixties many years ago when I started my car on a particularly cold morning and raced off to work without allowing any time to warm up. I was late to work and in a hurry. I drove lessvthan a mile in a 45 mph speed zone before getting on the highway at 60 mph. I got only as far as the next exit and pulled off into a service station. My car had overheated. It seems that even though my antifreeze was good to at least -10, I hadn't considered the windshield factor. The coolant had frozen and blocked the coolant circulation, thus causing the engine to overheat. It also blew my head gasgit.

    Now maybe this won't happen to newer vehicles, but I will always let the engine warm up before leaving or if I can't do that, I monitor the temperature closely while trying to keep the speed down until it approaches a normal temperature.

    Incidentally, I was living in Texas and the temperature was above zero by a little bit. In colder climates, a lot of vehicles are pluged in at night to keep the block warm.

  10. bud
    July 17, 2013 #

    The one about flashing the headlights does happen, and they don't care who you are. A woman in Vallejo,ca was shot last year for that and it was all over the Vallejo Times..

  11. Chris Diaz
    July 18, 2013 #

    Um myth #4 happened in long island about a yr or 2 ago. A family of 4 was murdered by ms13 gang members who drove at nite with there lights off waiting for a car to flash there lights. Story was confirmed by nassau pd.

    • spookiewon
      July 26, 2013 #

      Can you provide a link to the story in a local newspaper or on the Nassau police department's website? Every urban legend has lots of people insisting they know for sure it happened and cites some police department or police officer who 'verified' it, Generally the PD has never heard of it and/or the officer doesn't even exist. But in this case, if you check Snope's, you will find that the Nassau incident is specifically addressed. It wasn't the police department but the sheriff's office, and they mistakenly forwarded it to the fire department without verifying it first, and then the FD forwarded it to every department in the city. It was entirely false, and the Nassau county sheriff's department has said so.

      If you are going to insist that something is true, you need to provide evidence, in the form of actual links actually demonstrating the truth of the claim.

      http://www.snopes.com/crime/gangs/lightsout.asp

      • ThatDude
        September 14, 2013 #

        Wow, there sure are a lot of people quick to criticize and disagree. Maybe it did happen. I've heard of it in KY. Down in Ireland, Indiana, a man's car exploded at a gas station after he was using his cell phone. They had to replace part of the roof on the gas island. Gonna disagree with me, too?

      • Dave
        October 12, 2013 #

        Snopes is a biased, liberal, and inaccurate source for truth

      • White clowns
        October 18, 2013 #

        Snopes is a politically correct website that bases everything on a leftist agenda. They lost all credibility years ago.

    • Dave Seavy
      August 1, 2013 #

      I believe they would have flashed their headlights – not there headlights. I have done all I can to verify the story, and so far, not one reliable source has confirmed this actually happened.

    • Ignorant Guy
      August 10, 2013 #

      the biggest reason im suspicious of this myth is that cops pull over people driving without their lights. I think that's a faster way to get pulled over than speeding. So if a group of gang-affiliated men who are armed are driving around conspiring to murder someone, I feel like they wouldn't do it in a way that invited cops. This may be stereotyping but I think a car full of gang-members probably already looks obvious and suspicious enough to a cop without the added fact of no lights at night. Most of them I assume would find less dangerous ways of finding targets.

      • arch stanton
        August 31, 2013 #

        Yup

    • darellst
      August 14, 2013 #

      From all the responses I've read I think people believe what they believe and are not going to change their minds.

      • Fred
        September 23, 2013 #

        Yup, and the Earth is flat dadgumit.

    • herspanic
      September 14, 2013 #

      Um… it didn't happened . You can confirm it with Nassau County Police Dept that it never happened . You can also news archives and you will never find any record of it

    • Mark
      September 16, 2013 #

      This happened to me! In 1996 I was headed home from Long Beach to Montebello and got cut off by a Grand Torino on the 60 freeway (and there was no traffic to speak of). My pregnant wife say next to me, sleeping, so I flashed my lights at them. They slowed down, and as I approached, the passenger cocked a hand gun. I slammed on the brakes and his car braked a moment later. They were, after a few moments, far enough away that a shot from a handgun would have likely missed, and then they sped away. Got home 10 minutes later and called the CHP (didn't have a cell back then); the CHP said since he hadn't discharged his weapon, there was nothing they would do. Always good to be careful out there. But yeah, I would say "NOT BUSTED."

      • king
        September 22, 2013 #

        And it took you 17 years to tell this NOW!!???? Can you corroborate this story? What proof do you have?

      • Yourdumb
        October 17, 2013 #

        This one time I road a unicorn across the Atlantic Ocean and a whale shot a dolphin.

    • Austin
      September 18, 2013 #

      He's unfortunately incorrect about nearly everything here with the exceptions being that only high performance engines need higher octane fuel and red car insurance premiums.

      Put some sugar in a pot on the stove. Burn it. Note what happens to sugar when it burns. If you believe that isn't bad when its happening to your engine parts, then you obviously have no knowledge of how an engine functions.

      Ever notice that an engine might knock when you first start it even a newer engine with relatively low mileage? That's because when your engine is turned off so is your oil pump. Your oil runs back down into the oil pan and the engine and oil cool. When you next start your now cold engine, for a few seconds, there is no oil in it. You engine, in most cases, has an optimal running temperature of 195 degrees f. Until your engine block, coolant, and oil reach their optimum running temperature any hard driving you do WILL be doing damage even if minimal. You're taking off years. The carburetor is only PART of the reason to warm an engine.

      Gang members in certain areas of our country have in fact since the mid 90's used chasing down flashers for initiations. It happened to a Virginia Beach family when I was in high school in the area and it was widely publicized. The practice continues today. They drive on sparely populated streets in areas known to be the turf of opposing gangs to avoid killing their own people or families of other members of their own gang.

      Lastly shooting the gas tank of a running car CAN cause it to explode. First off the tank is pressurized so it WILL expel gasoline quickly if punctured. Now that has spraying out is going to have to go somewhere. Not many places to go without hitting somethin hot, brakes, rotors, exhaust, etc. Care to take a guess what would happen when fumes and spraying gas mist hit red hot metal?

      Why would someone who obviously possesses NO automotive knowledge write an article about automotive myths without wasting time on things like research? Terrible article, nearly devoid of anything factual whatsoever.

      • Robert
        October 26, 2013 #

        Honestly your car knowledge you claim, you should know that gasoline as a liquid isn't unstable enough to explode unless you give it some outside ignition source. Such as a flame. Unless someone is shooting flaming bullets at you a car will not explode from a bullet to the gas tank. It won't just combust like you claim from spewing onto hot components on your car. Get a bucket of gasoline and drop a cigarette in it, itll not ignite, but drop a lit match into it and it will. So don't insult the whole article if you clearly aren't well informed either. My knowledge comes from years of vocational training and experience. Yours likely comes from lethal weapon.

      • John Q Bellicose
        January 24, 2014 #

        @Austin- As For This Article I Do Believe It Was Poorly Researched; However, While U Say The Author Is No Expert, U Might Want To Know That A Gas Tank On A Car Is NOT Pressurized!! There Might Be A Small Amount Of Pressure That Builds Up Inside The Tank From The Fuel Vaporizing, But There Are Vents That Allow The Pressure To Slowly Bleed Off! Cars, Trucks, & Etc. Have A Fuel Pump That Sends Fuel To The Engine! Older Cars Used A Mechanical Fuel Pump That Was Driven By The Engine, But Newer Cars Use An Electric Motor (DC Powered) To Run The Fuel Pump, Which On New Models Is Inside The Gas Tank, And Is Also VERY Expensive To Replace!!!!!!

    • reformed2
      September 21, 2013 #

      "Myth" #2 – If you live in northern US and you don't give the oil in the pan time to warm a bit you won't have oil in the upper portions of the engine thereby risking breakage.

    • Bobby Killough
      October 20, 2013 #

      People let their car warm up in the cold BECAUSE….when starting a car most all of the oil is in the oil pan and not up in the moving parts of the motor…so if u just start and go your basically putting stress on the motor before it has had a chance to move that oil up and out of it's resting place in the oil pan……cold weather makes the oil a little thicker than normal…..hence YES let your car warm up that oil and get it to where it needs to be before putting stress on the motor…..I've never even heard mention of anything but this concern in cold or any weather….DUH!! Lol

  12. Mulah
    July 18, 2013 #

    No4…Wait what? Beginning of the month when I still have money that's all my car gets, end of the month no more cash, cheap fuel is your friend :)

  13. harry
    July 20, 2013 #

    Myth #4 1986 in a Chicago gang infested neighborhood a Motorcyclist was run over & killed by car with lights off after he tells the driver "your lights are off". true or false widespread or not I have not signaled anyone since then that their lights are off.

  14. Mike
    July 21, 2013 #

    myth #4 has been around a lot longer than 1993, it was a known fact in the late 70s and early 80s that gangs did indeed select their victim from the headlight flashes.

    • larz0
      August 9, 2013 #

      A known fact? More likely a known urban legend.

    • Jackson
      October 24, 2013 #

      This can't be true because I signal them all the time to turn their lights on. Then of course I am packing. Haven't had any takers yet. Jackson

  15. michael
    July 21, 2013 #

    Im not sure what mechanics institute you went to but you should get your money back. Your suggestion that heating an engine is a waist of time is false because it give the different metals (piston rings, being the most important) time to expand before the stresses of higher r.p.m.s are acheived. Your engine doesn't care if its 20° or 50° all it knows is that its not 190~230. Also, higher octane fuel is more combustible. More combustion=more power. People don't spend 7~9 bucks a gallon on race fuel so that it will fire earlier. It burns hotter and fire under more compression. Don't mislead people with facts on things you know nothing about. Its dishonest.

    • tom jones
      July 25, 2013 #

      You have the octane wrong, lower octane gas is more combustible. Thats why high octane is used in performance vehicles, the higher compression needs fuel that resists detonation. Using lower octane in a performance car is bad because it causes the engine to detonate too soon. Both high and low octane fuels have the same amount of energy, the rating is simply a measure of resistance to detonation, higher the number, the higher the resistance to combustion. Don't spread misinformation when you don't know what you're talking about.

      • Sean fuhlman
        July 29, 2013 #

        The timing on your car dictates when and what order your spark plugs fire at. Not the octane rate. And your wrong higher octane explodes harder. That's why jet fuel is what like 110 or higher.

      • mike
        August 18, 2013 #

        Agreed

      • Ron
        September 17, 2013 #

        Actually, you let a cold engine warm up before loading it so the oil that drained down into the crankcase has a chance to circulate up and re-coat the cylinder walls and bearing faces, rocker arms, etc. You can actually hear the engine change when the lubrication has returned – if you know what to listen for.

      • John Phu Nguyen
        September 21, 2013 #

        You are right. I don't know why people are claiming stuff as fact when they are not.To Sean Fuhlman: the timings are the ideal detonation rates, not the actual detonation time if you use low octane fuel. Also, Octane also does not indicate how much energy concentrstion is in the gas. For example, E85 gas has less energy but that doesnt lower its octane score. Diesel engines, on the other hand, benefit from lower octane. That's why diesel fuel would otherwise destroy a gas engine, because low octane doesn't mean low ignition energy.

      • docman
        October 8, 2013 #

        The octane is the percentage of 8 carbon fragments (hence octane) in the gas. More octane, higher ignition temperature. Putting high octane fuel in a car not needing it is a waste of money. Putting low octane fuel in a performance car may damage the engine. The highest octane is 100. Piston driven aircraft use 100LL (low lead) 100% octane and some lead to preserve valves . Jet fuel is essentially kerosene and octane does not apply.

      • Adam
        November 17, 2013 #

        Diesel you don't have this problem

    • Doug
      July 30, 2013 #

      Tom is absolutly correct. Only higher compression engines or vehicles with heavy loads like motorhomes and trucks pulling trailers benefit from high octane fuel. If your vehicle knocks or pings when under load you may need a higher octane fuel or your ignition timing is maladjusted. If you drive an older car a mechanic can adjust the "initial" timing at idle. The timing advance system can also affect knocking/pinging and performance if not adjusted to operate properly. If you drive a car that is less than 20 years old and regular gas does not cause knocking, then you are wasting money putting premium in it. Jet fuel is a different animal altogether. It is more similar to kerosene than gasoline.

      • Trevor
        August 8, 2013 #

        Tom is correct. Low octane fuel ignites easier than high octane. Using low octane in a high compression motor (bmw for example) causes the fuel to ignite before the spark plug fires, which is called pre-ignition. It fires before the cylinder reaches top dead center causing horrible forces in the engine, and makes the "knock." Please don't post what you've heard or what you think you know. If you doubt any of this look it up in a factual place.

      • Austin
        September 18, 2013 #

        Tom is absolutely INCORRECT, as are you in your support of his statement. Octane is the hydrocarbon in gas that ignites. It IS the combustible element in gasoline. A higher octane rating means a higher concentration of that combustible hydrocarbon thus giving HIGHER combustion. Higher octane = higher combustion. Whole line of folks who know noting about cars talking before they bother to educate themselves.

      • arch stanton
        September 18, 2013 #

        Austin, You’re sorta right but not really. Gasoline has lots of chemicals in it that ignite. Octane is indeed a hydrocarbon (a family of hydrocarbons actually) which makes up much of gasoline, but the “octane rating” is a measurement of the temperature and pressure the whole blend ignites at (it’s resistance to auto-ignition). It is called “octane rating” because it uses an isomer of octane and n-heptane as a standard for the measurement. There are actually several different ways to do the measurement and the same gasoline will have different values depending which one is used.

        LPG has a very high octane rating even though it has little to no octane.

        Wikipedia is a good place to start for this (since it is not a subject with significant political implications). See: Octane, octane rating, gasoline and assorted links.

        hth, arch

      • Andy
        January 9, 2014 #

        @ Docman…nice post but when I was a kid Richfield gas stations listed their "ethyl" gasoline at 102 octane. So there was gasoline with an octane rating over 100. Why was that?

    • phil
      August 3, 2013 #

      Michael, I could not agree with you more. very well written response to this article.
      I drive a 2005 ford f150. even in hot weather here in Florida, after leaving work I let mine idle for about
      three minutes before driving off. all for the same reasons you have stated. well done sir……

      • paul wayco
        August 10, 2013 #

        I see there are a lot of ideas here covering the high octane fuel. going back to the point of should you use premium fuel in a low performance car?. Yes you should IF it is new enough 1992 and up,, IF there is a computer control timing system. the system will learn the detination point of your engine timing, and then use a much wider range of spark advance. giving smoother power, better emissions, and significant fuel economy boost. I have done this for years. preached it to customers and had very positive responce. if you dont know if your vehicle has this type of control, then take a trip, with and without high octane fuel. If you get better fuel economy, then do the math,it will be obvious if its worth the few bucks per tank.

    • hunter
      August 18, 2013 #

      i was thinking along these lines.

    • caribcrazyjim
      August 19, 2013 #

      Top Fuel Drag Cars warmup for how long, not needed

      • EW
        October 8, 2013 #

        How many miles are Top Fuel engines driven before they require a rebuild? Only one quarter mile.

    • Grant
      October 27, 2013 #

      Winner, winner, chicken dinner. Best answer yet.

  16. Susan Burns
    July 22, 2013 #

    Chris Diaz: To make a claim like this that you want people to take seriously, you need toy provide proof to site your source. Do you have a link to an article that backs up what you are saying? The problem with urban legends is that people swear they are true because simeine they respect and believe told rhem it was true. It travels from person to person until it seems legit. Snopes.com carefully researched this and found NO evidence of its truth.

  17. LkBarr
    July 22, 2013 #

    My favorite automotive urban myth is that cell phones cause fires at the gas pump. This myth persists despite numerous reputable sources (FCC, Petroleum Equipment Institute, and MythBusters) debunking it. While a cell phone does emit a small electric charge, the charge is so small that the chances of a gas pump fire are next to impossible. The only documented "case" was a gas pump fire in NY, and it was a fire captain who initially blamed the fire on a cell phone. He later recanted and said the fire was caused by static electricity instead. This belief continues to be perpetuated by gas stations and cell phone companies who issue warnings because they are afraid of lawsuits. I've also seen this falsehood presented as a news story on my local TV news. I won't document my sources here: google "cell phone gas pump" and a long list of articles will come up.

  18. adrian
    July 23, 2013 #

    A vehicle does need to be warmed up to save gas, even fuel injection. When the car is cold the engine goes into open loop, once it is warmed to operating temperature then it goes into closed loop. Dude you need to get your facrs straight. Look it up, research then report it.

    • scared of gangs
      July 25, 2013 #

      Myth, flashing headlights, a man was killed back in the early 2000, he was with his daughter and he flashed his headlights, he was shot and killed. Montana or rialto, ca on foothill Blvd.

      • spookiewon
        July 26, 2013 #

        Link to local newspaper story please or it didn't happen.

    • spookiewon
      July 26, 2013 #

      Yes, but it it takes less than a minute for this "warm-up" to occur. You car is adequately "warmed-up" in the time it takes to buckle your seat belt and set your radio station, FFS. There is no need to idle a car for ten or more minutes even in bitter midwest cold.

      • Sean fuhlman
        July 29, 2013 #

        What's your average temp in winter where your from? How long does antifreeze take to warm up so your heater works properly?

      • Bryan
        September 13, 2013 #

        I'm no expert but I thought with these new computers and systems , that it made it less necessasary for the newer cars to be warmed now a days , or maybe only gmc vehicles ?

    • A butler
      August 7, 2013 #

      That is right. Ever notice how much power and response a vihecle has until it warms up. The computer is in a open or close loop depending how it is set up

      • ShunkW
        September 5, 2013 #

        Actually I have noticed in nearly every motorcycle I ever drove that a "cold" engine has much more power than a hot one. In cars I have never been able to tell any difference.

      • WS6Chef
        September 9, 2013 #

        Computers are not the reason that a car is more crisp and responsive when they are cold. It has to do with the oxygen density of air. Cold air is more dense with O2 than warm air. Once a car gets to it typical operating temperature, the air that enters the intake manifold will begin to be heated. By the time it reaches the piston chamber, it is considerably warmer than it was outside of the engine bay. Go to any drag strip and look for older race cars. Chances are, there will be bags if ice sitting on their intake manifolds. They also will have coolers full of ice water to replace the water in their radiators between passes. Racers go to great lengths to get the coldest and most oxygen dense air that they can. Hence "Ram Air" and "Cold Air Intake". Engine heat tremendously effects performance.

      • jag
        October 12, 2013 #

        Its because the engine and pistons haven't had sufficent time to expand, so as a result of being restricted the rings are tight to the piston walls creating a tighter inner seal, as the motor heats up, the expantion let's some of the gases escape past the rings and the result being a slight loss of power, so small u barely notice but u do! So there's ur answer for y motors run so well on start up…

    • paul wayco
      August 10, 2013 #

      Yes,, warm it up! on many points from mechanical physics to comfort and driveability and safety. the emissions that are produced by driving a freshly started engine are huge comaired to one that is at least 150F degrees. Thats for info to the Green Gangs. But also, the amount of wear and tear on engine parts happens Most, during that warm up period, so be easy on that spinning mass of metal until the heat is stabil and oil is flowing nicely. If you dont, then expect early engine failures. these facts are why emergency vehicles and or generators have heaters to keep the ready to perform with ease.

      • chadbag
        September 18, 2013 #

        This makes no sense. The cold engine sitting there warming up is still running and doing engine wear and tear. Modern cars do not need to be warmed up, and in fact you may cause more engine wear and tear because an idling engine won't build up oil pressure as fast as one going at a normal RPM for a slow speed. Most experts recommend no warm up, but do not stress the engine with high speeds or revving until warmed up. Driving through your neighborhood for a couple of minutes at 20-25mph to the main road before you rev higher and go faster should do it.

    • Mechanic
      August 19, 2013 #

      Really? What mileage are you getting while sitting there warming up? Zero MPG! Even if your car gets half of the warm-engine MPG when it is cold, it will definitely be better than zero.

  19. Facts
    July 25, 2013 #

    It is laughable how many of you believe the gang initiation thing, and your anecdotal ("It was all over the news where I live!") evidence is even more absurd. I challenge any of you who believe this crap to link to even a single reputable source for your information. Go on, prove me wrong.

    And yes, you should warm up your engine in cold weather.

  20. Bill Reed
    July 28, 2013 #

    Regarding the cold engine debate, most damage to your engine occurs at the instant of start up. Your engine goes from effectively 0 RPMs to 2000 RPMs immediately. Allowing the engine to warm is really only a benefit to the driver on cold days.
    If you live in an area with extreme cold, making sure your oil is the correct viscosity for the season can help reduce wear.
    Thank goodness our car's computers are smarter than us!

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