Conservation tip: Idle engines are the devil’s tools

Should we all be turning off our engines at stoplights? Driving up to Lake Tahoe last weekend, I pulled off for gas in Auburn. I turned off my engine at the stoplight, which earned me a curious glance from my passenger and the comment “Don’t you know that turning your engine off at lights causes more pollution and engine damage than just letting it idle?”

Not only did I not know that, I suspected he was wrong. A quick dig proved two things: first, that idling your engine is wasteful; second, that warming up your car is unnecessary, even counterproductive.

The EPA’s own anti-idling program provides conflicting advice: it’s always better to shut down; shut down if you’ll be standing still for over five minutes; for thirty seconds; for ten seconds.

The Sierra Club agrees with the ten-second rule, and this is what I recommend as well. If you’re going to be stopped longer than ten seconds, turn you engine off.

Energy Solutions Alberta adds another suggestion: never let your car warm up more than thirty seconds before you start driving.

The EPA agrees, and states that longer idling actually causes engine damage. The owner’s manual in my Audi warns, “To avoid unnecessary engine wear and to reduce exhaust emissions do not let your vehicle stand and warm up. Be ready to drive off immediately after starting your vehicle.”

So idling is bad, and warming up your car unnecessary. But many people continue to warm up their cars anyway for another reason: interior temperature. Though it may pollute and be hard on your car, warming a car up insures that the car is toasty inside when it comes time to drive. Hence the proliferation of remote starters in the northern climes.

This issue has been largely addressed in Europe, where millions of cars use fuel-powered heaters that are separate from the engine. These little heaters produce about 4% of the emissions of an idling engine, and have the secondary benefit of actually warming the engine itself prior to starting, which reduces wear. Manufacturers include Eberspaecher and Webasto. While far from cheap, these heaters are a responsible investment, especially in very cold areas.

Idling cars are also awfully easy to steal. Our local paper, the San Jose Mercury News, has published articles twice in the last two years documenting the rash of winter thefts of cars warming up in driveways. Thieves cruise neighborhoods looking for plumes of exhaust in driveways and drive away with your car, no violence or special hardware needed.

So do your car, the environment, your local police department, and your pocketbook a favor: follow the ten-second rule and skip the morning warm up.

Author Bio

bret

Comments Disabled

  1. Nick - February 22, 2006

    You can’t be serious about not warming up a cold engine. What about the internal gaskets, seals, metal components, fluids, and their different rates of expansion / contraction? If you are going to recommend driving with a cold engine, do the responsible things and warn of the potential damage that can be caused.

  2. Blaise - February 22, 2006

    Look, if the manufacturers are the ones stating that it is actually unnecessary to warm up ones engine, then I believe that their studies are msot likely to be true. Now, that could be a reason to misdirect the buyers of said vehicles in order to sell more replacement parts. Are manufacturers actually so greedy and ignorant of their own environment (one in which they too must inhale from) that they would rather have the temporary monetary benefits rather than the long-term benefits of resperatory health? Who is to say? For now, I will have to go with the manufacturers. Oh, and the facts. Just have to do the research.
    Peace out!

  3. Nikita Reva - February 22, 2006

    Nick is absolutely right, driving a cold car is one of the most dangerous things you can do to your engine. A car is most inefficient when it is cold; consuming on average 300% more fuel when engine temperatures are below 150 Fahrenheit. Although a car will enter its “efficient state” quickly if driven cold due to higher RMP’s, the potential for engine damage is exponentially greater than a car driven warm. Due to the equilibrium between engine RPM and fuel consumption, I?m confident in saying that a car warmed up for reasonably short period is actually more efficient per miles driven than a car driven cold. The golden rule with warming any engine is low and steady RPM, this allows the oil pump to start building oil pressure as it lubricate engine internals. I’m a strong supporter of conservation and efficiency, yet my auto engineering background tells me that driving a car cold is most certainly a bad idea.

  4. John - February 22, 2006

    The Car Talk guys seem to side with the view that idling is unnecessary and wasteful. I think they imply that engine wear in a modern car would be too trivial to be concerned with.
    http://www.cartalk.com/content/columns/Archive/2003/May/03.html

  5. Ed - February 22, 2006

    For a number of years, new car manufacturers’ manuals have been saying not to warm up cars. This recommendation has been supported by both CarTalk and Consumer Reports. I have also seen articles in other places saying the same thing. Modern cars are designed to warm up as you drive. Coolants, lubricants, metals and other materials used in modern cars are vastly superior to those used 15, 20 or 25 years ago.

  6. Steve - February 22, 2006

    I drive a Prius and its gas engine doesn’t even turn on until I’m moving. No warmup is necessary, or even possible for that matter. To me, it indicates that warming up an engine in any new car is probably not needed.

  7. Daniel - February 22, 2006

    Well, let me see…as a lifelong Republican, I’m surprised no one has seen the obvious. I contacted FEMA, the DNC and the RNC about Hurrican Katrina and being stuck in traffic jams so long your car literally ran out of gas.
    The answer is, an electric car, which uses 0% consumption of petroleum while the car is not moving. A hybrid is the only vehicle to have. No matter how slow traffic moves, no matter how long you wait at a red light, you only consume gasoline enough to equal the expenditure of energy of movement.
    When the next big hurricane hits, some Americans will be prepared with their hybrids. They will not run out of gas stuck in traffic while their internal combustion counterparts run out of gas. If you were caught in a disaster, which kind of car would you like to be driving? I hope and pray that enough Americans take heed that when the next Katrina hits the amount of hybrids will be at critical mass.

  8. vicb - February 22, 2006

    Thanks for your comments. When I was living in upstate NY, where cold was perfected if not invented, we had an electric block heater set to a timer and the vehicle’s interior warmed up much faster and the engine was warmer so had less wear, too (this was also much cheaper than the pre-heaters mentioned in the article although it was useless away from an electrical source).
    Car and Driver recently ran a Honda hybrid with and without the engine idle shut-off feature and found surpringly better fuel economy when the engine was shut off at idle (see their website and key in “frugalympics” or Civic Hybrid). I have therefore taken to shutting my engine off while stopping when the engine is warm, and find that it is just one factor among many but it certainly can’t hurt the mileage or the pollution. It may put slightly more wear on the starter, but modern starters are pretty reliable and the engine is tuned well enough to take little effort (my battery is going on its sixth year). It also seems to help put me into an economy-driving mode.

  9. Reed Braman - February 23, 2006

    No one has mentioned the amount of energy it requires to start a car. Not knowing a whole lot about automobiles this may seem naive, but it requires an immense amount of energy to start such a large piece of equipment such as an engine. (i.e. surge power vs. running power consumed when dealing with electric motors. or if you prefer coefficients of friction [granted on a much smaller scale]). This may decrease as a function of temperature but I would still think that the short time of idling would consume less than starting the engine. This energy may be supplied by the battery and therefore not consume petroleum; however, the battery has to be recharged and that requires petroleum (increased usage of alternator = less mpg, not to mention anytime there is a conversion of energy there is a significant loss of efficiency). I was once told (albeit hearsay) that if you’re just running into the house/store/whatever that if you were going to be less than five minutes you should leave the car running. As for the warm-up period I have no intelligent input; after all you get 0 mpg for idling.
    Very commendable discussion thread but I would like to see some data or “expert” (i.e. manufacture, EPA/DOE, national lab, etc.) opinion to add some weight behind one side of the arguement or the other.

  10. melisa - February 23, 2006

    Hi guys, all this car talk gets me thinking. So those of you who are worried about putting your engine in “Danger”, are you thinking of the real consequences of idling? Are you familiar with the fact that if the earth were the size of a basketball, the biosphere, which we live, breath, and grow our food in, would be roughly the thickness of a piece of saran wrap? Yes, thats the air , soil, water etc. So what are we putting in danger here? who needs a car when you cant breathe clean air? what’s more important here? your car, or the only home that we have? I live in Canada, and it gets damn cold here, and I don’t belive in idling. We could go around in circles arguing about engine wear and tear, etc, but I think the message here is that it’s not our vehicles that are important, it’s our planet! And if you have to be convinced that your creature comforts won’t be harmed in the making of a cleaner planet, than that’s pretty sad! Choose…Life or toys! ps I wouldn’t undermine the seriousness of the situation that our planet is in!

  11. Jonathan - February 25, 2006

    What about the wear/tear to your STARTER everytime you have to restart the engine? seems like it would cause some serious life expectancy adjustment

  12. Howard - February 25, 2006

    The after 10 seconds rule is great advice. To ally fears, let’s think about it:
    1) No warm-up is NOT destructive to the engine if the in-motion warm-up is done right. Boogying off with a warm engine gives a false sense of security. What of the other parts? Letting the entire car warm up together prevents hidden damage to the transmission, universal joints and differential. The key is to not overstress any system on the car, not just the engine.
    2) The fuel needed to start the engine is exponentially reduced as the engine approaches running temperature. Further, the starter does not get overstressed if the engine is warm. A well maintained battery recharges quite quickly as a normal function of driving the car and does not use nearly as much fuel as idling the car.
    3) Not idling heats the car as efficiently. The engine block has a huge amount of thermal intertia, just like the ocean. Any heat generated during running the car in the warm-up period will be dissipated throughout the engine block while the car is shut down. This allows cold moving parts to heat up without moving. Those closest to the heat source – the piston, camshaft, crankshaft and circulating oil – will benefit the most, and the driping oil will heat the oil in the oil pan.

  13. Wendy - March 15, 2006

    Please reconsider the idea of turning off your engine at red lights. If you are alone, the time it takes to restart your motor is your business. If three cars in a line of twelve shut down at each light, everyone behind them idles that much longer. In a perfect world a car starts in five seconds, but in reality non-new cars may take significantly longer to get rolling. How about encouraging drivers to start slow and easy instead of jack-rabbitting away to get stuck at the next light.

  14. Adan lemus - March 15, 2006

    [Ed. note -- this comment has been edited to remove the obnoxious bits. We want to keep comments open to all points of view, but we don't feel the need to tolerate insults. Thanks.]
    [Ed. note -- the funny thing is, the comment is both more readable and more persuasive without the gratuitous language. Kind of makes you think, doesn't it? I have no idea whether the commenter is right about this matter, but now at least I'm inclinded to find out more.]
    Does anyone know what a catalytic converter is? The catalytic converter is a device that lowers Hydrocarbons (HC), Carbon Monoxide(CO), and in the case of some converters Oxides of Nitrogen(NOx).
    The catalytic converter will not begin to function till it reaches a temperature of 1,500 degrees. If you do not allow your car to warm up you are driving you car with no functioning catalytic converter. All you are doing is pumping out all of those dangerous gases.
    I have been an ASE certified technician for ten years. I am currently working for and have been working for a well known southern Californian Ford, Lincon, Mercury dealership for the last nine. I am a certified smog technician. I hate to be the one to inform every one but what your owners manuals say is not true. The E.P.A for the most of my decade of experience has been wrong 90% of the time. They constantly make suggestions that they eventually have to retract.
    Don’t be so quick to just believe what the auto manufactures and E.P.A say on such matters. Do some research and think for yourself. I have been fortunate enough to have a job that allows me to learn and figure these things out for my self.

  15. Adam Lemus - March 17, 2006

    To the Ed.

    I should thank you for the edit of my commit of Mar 15, 2006, you are absolutely right in doing so, TO anyone whom I may have offended, you have my most Sincere of apologies, but still please take my advice, Do your self a favor and learn as much as you can about this subject about. There is plenty of unbiased source material about modern automotive emissions technology

  16. Matt Childress - April 19, 2006

    Thus spake Adam Lemus:

      If you do not allow your car to warm up you are driving you car with no functioning catalytic converter. All you are doing is pumping out all of those dangerous gases.

    And while you’re waiting for your vehicle to warm up, is it not still pumping out all of those dangerous gases? Methinks it’s better to get some mileage for the damage done, instead of sitting in the driveway. Especially if your first few miles are low RPM.

    Then again, zero emission EV’s don’t have the warm-up question, and electric heat is instant-on for the cabin as well. When’s the last time you had to wait for your hairdryer to warm up, or your electric blender to rev up? With EV’s you don’t have to be concerned with turning them off at stop lights — when you’re going, they’re on, and when you’re stopped, they’re essentially off. Either way the pollution is contained at a single point source, either the local power plant (which gets stricter emissions regulations placed on it yearly) or your own hydro/solar/wind station.

    And should you think range is a problem, I’ve read that 80% of Americans commute 40 or less miles a day, and 50% commute less than 20 miles. Wish I could find a decent citation for that stat, but it’s well within the range of current EV’s. EV’s can blow any production sports car off the line — see the video of the Tango at http://www.commutercars.com. Of course most choose economy of range over power http://www.twike.com, but they are still quite zippy. Definately NOT your grandma’s golf cart that she uses to get around her Florida retirement villa.

  17. Adam Lemus - May 14, 2006

    Dear Matt,
    I find your comments interesting. There is a difference between a car sitting at idle and driving under a load even at low revs. While the car is sitting at idle its emissions are substantially lower than when it is on the move.
    Also, there is no such thing as zero emissions anything. Anything that performs work creates an emission of some sort. Yes your EV does not produce hydrocarbons but it produces electro-magnetic radiation that is just as bad, if not worse. Ever hear the joke, “He is that way because the house he grew up in was underneath high voltage lines.”

    Just because you cant see it does not mean its not there…..

  18. mike - May 29, 2006

    i didnt believe the dont warm up your car thing, but it is actually true. i have been informed that a warning label that is known to be on new bmw’s said do not warm up your, just drive off after starting, much like the audi in the article.
    i think the important thing is to drive slow, taking it easy until operating temperature is easy.
    as far as the 10 second rule- how much gas does a start up require?? probably varies by engine size, but i think consumer reports claimed one minutes worth of idling. In my opinion, whatever that amount is that the engine requires to start up is the maximum time the car should be left idling.

  19. Anonymous - May 31, 2006

    Could it be the oil companies recommended warm-ups? Idling engines, especially a few million, each morning, burn lots of fuel. Big business influence on government creates a strong following. (e.g. Replacing animal fat with vegetable cooking oil made from genetically modified organisms, is this really good for your body? The government has been pushing the believe that vegetable oil is better than animal fat without adequate research.)
    Worried about engine parts wear? How long after start-up does it take an engine to distribute all fuilds to the all necessary parts of the engine? Isn’t an idling engine still working, moving parts as it does during driving? I don’t take off from my driveway at high speeds. I don’t run at high speeds down my neighborhood streets. Could this type of engine use assist with the warm-up process?

  20. Adam lemus - June 2, 2006

    Its not the lubrication you have to be concerned about its the smog equipment, with out letting you car to warm-up you are not giving it the time to activate its emissions equipment like I said before, The catalytic converter will not begin to function till it reaches a temperature of 1,500 degrees. If you do not allow your car to warm up you are driving you car with no functioning catalytic converter. All you are doing is pumping out all of those dangerous gases.

    And to respond to MATT CHILDRESS who said, and while you’re waiting for your vehicle to warm up, is it not still pumping out all of those dangerous gases? Methinks it’s better to get some mileage for the damage done, instead of sitting in the driveway. Especially if you’re first few miles are low RPM.

    Like I also said before, there is a difference between a car sitting at idle and driving under a load even at low revs. While the car is sitting at idle its emissions are substantially lower than when it is on the move. Everything I’m saying is for a purpose to help people understand automotive technology, this for me is not a subject matter that I have just causally looked into it’s my Job and Lively hood to know about these things.

  21. Anonymous - June 6, 2006

    Anonymous points it out well: Recommending the continued practice of warming up a car once one figures the gross amount of fuel wasted by 10 minutes warm-up idling per day per car worldwide when the manufacturer explicitly recommends against it seems… odd… at best.

    The catalytic converter is one of the LEAST important parts of the environmental equation at this point in time. More smog could actually be the lesser of two evils, if we can’t find a way to reverse CO2 levels:

    Smog causes Global Dimming (see Wikipedia/Google) which oddly enough is a GOOD thing as it counterbalances the effects of global warming (via CO2 & N2O, gasses the standard 3-way catalytic converters do not in fact reduce, but increases by oxidizing carbon monoxide and other hydrocarbons). Current smog reduction efforts in the first world (while ignoring CO2/N20 emissions) have actually hastened global warming by reducing the amount of smog, thereby reducing the offsetting effects of global dimming.

    Burning less fuel by not idling results in two things: debateably more smog as the catalytic converter isn’t at peak effeciency (which, as pointed out above, ironically has positive side effects), and a heckofa lot less CO2 released from wasted fuel burnt at idle when multiplied accross every vehicle on the planet.

    As to the arguement against EV’s that “electro-magnetic radiation that is just as bad, if not worse,” is wrong on several levels. First, EV’s do not operate nor produce light energy — the more informal and less drastic-sounding name for EM radiation. They produce about as much of an EMF as an electric clothes dryer (approximately the same voltage & electric power). The difference between the ‘high voltages’ of EV’s (360V) are orders of magnatudes less than high-power transmission lines (33-1200 kV). As a non-scientific comparison of the comparitive dangers of the emmissions of the two types of vehicles, for decades humans wishing an early exit have sealed themselves in a garage with their ICE car running, with a great sucess rate. To date, standing next to a clothes dryer hasn’t killed anyone… unless you get in it ;-) While still in debate, the current mainstream scientific view is that powerlines are not likely to pose an increased risk of cancer… but then, the current mainstream scientific view is that idling/warming up your car is a bad idea…

  22. linda cantrell - June 24, 2006

    I have TWO neighbor GUYS who feel they need to WARM UP their big pick-ups every morning YEAR AROUND for 15-30 min. The noise is irritating, (wakes me up) to say the least plus the fumes are disgusting.
    One is a NEW truck, the other a 60′s model with a new engine, both LOUD. Should either consider warming up at all in Seattle, where we rarely have freezing weather?
    How does a GAL approach macho guys to tell them something like what ya’ll have said against warming up the engines? They ARE my neighbors! Linda

  23. Nismo - June 29, 2006

    I agree with the TECH guys. You need your car to warm up soo all the lubrication and gets past through the engine equally. Since your ideling and not moving you are not putting load on the pistons and the crank and all the sensitive areas that need lubrication. Ive been warming my cars for year; summer time 2-3 min tops then drive slowly and gently, winter 5-7min then drive slowly and gentle. One of the cars is allmost 300K on the odometer and everything runs fine. Plus where i live theres no strict smog laws and i run most of my cars without the stupid catalic converter, just a good old straigth pipe =) I find all this safe this dont harm this is buncha Enviromentalist B.S.

  24. Claire - July 1, 2006

    I think Click and Clack, the Tappett brothers on NPR came down on the side of not “pre-heating” the cars, just driving a little bit slowly at first. Taking off the catalytic converter is a bad idea — most of the air quality improvement in the US over the last 20 years (yes, the air quality has improved as far as smog and ozone goes) is based on improved technology. Our focus should be on investment in technology to solve the pollution problems associated with transportation. I’m not willing to say we should create more smog to save ourselves from global warming, especially considering that smog’s particulate matter is not good for our lungs or hearts. Its probably not healthy for many of our bodily systems, we just dont’ know it yet.

  25. matthew - July 5, 2006

    Hey GAL,
    If asking them doesn’t work, and if the fumes are unbearable, ( I know the exhaust smell is worst than cigar smoke and ashtray smell. ) report the situation to your city epa or your state epa air quality division. ( The exhaust does get into homes. It can cause headaches. )

  26. Anonymous - July 5, 2006

    I think the true reason for the 15 to 30 minute warm-ups is for creature comfort. I don’t think wimps that, like it nice, warm and cozy in their vehicles, would trade this comfort for saving the earth.

  27. Jill Ingels - July 6, 2006

    I don’t mean to sound like a jerk but it seem that every one here is ignoring proven facts and sticking with opinions. It almost seems that nobody is listing to the tech guy, California happens to have the strictest emission laws in the country there smog techs have to go through extensive training before they get there license to perform smog checks. I did what the tech guy suggested and did some research and this is what I found

    Fact: cars need to warm up for up to 5min to allow cat-converter to start functioning.

    Fact: Engines need proper time to reach operating temperature to prevent undesirable problems like blow-by with occurs when the cylinder ring do not expand properly do to pre-mature loads placed on the engine.

    Fact: Some manufactures do not recommend warm ups because of specialized emission systems in cretin models in other words what apply to a 2006 BMW will not apply to a 95 Ford ranger.

    Fact: “Electro Magnetic Radiation” is real and EV’s do emit IT

    I brought up the issue of Electromagnetic fields to my professor, first he said that the tech guy is on to something that has been a concern for scientists for the last seven decades, unfortunately it hasn’t been getting the attention it deserves. As it was explained to me Hybrids and EV’s will only escalate a all ready serious environmental hazard, my professor said that the best way to go would be to keep the internal combustion engine but change the fuel to something more environmentally friendly like Hydrogen or E85

  28. Ms dickerson - July 6, 2006

    I would not suggest tatel telling on people to the EPA, One I don’t think there is anything that they would be able to do about it., “and if they can I fear for this nation ” we as people have to live with cretin things in our lives I think we should just learn to deal with it don’t you think ? I live under a flight path for police helicopters there loud and annoying but I have accepted the fact that there are there weather I like it or not

  29. matthew - July 6, 2006

    If they are polluting someone’s area, sure the EPA Air Quality Division has a duty to limit the time, if not stop, a vehicle which sits motionless wasting fuel and exhauting harmful fumes that eminate into another person’s home. Anyone familiar with “Second Hand Smoke?” How about a new term “Second Hand Exhaust?”
    There are reasons why most cities don’t allow semi-trucks to be parked in residential streets. Could one of these reason have anything to do with emmissions?
    What it boils down to is everyone, especially corporations, learning to be good neighbors. Good neighbors respect the law, not only government law, but the law of nature.
    For the TECH reliant: In any of the operating manuals, Are there instructions to run, idle, an engine for 15 to 30 minutes or any length of time? Is there a warning that engine damage will occur if it is not left running for 15 to 30 minutes or a set amount of time before operating? One US Gov agency in the Dept of Commerce has instructed its employees not to idle vehicles for warm-up. Once the heater is putting out heat, does this not indicate the engine is warm and ready?

  30. Nismo - July 11, 2006

    15 min is tooo long… all you need is 3-5

  31. Nismo - July 11, 2006

    You nature guys still dont understand that if you start and start driving right away the engine hasnt warmed up, seals are not properly set, oil works best when its hot not cold… And you are allready driving your car that is cold and makeing your engine push 3000 lbs+ while it hasnt reach its optimume temp. The reason why manufactures dont want to warm up is because of stupid emmisions systems on the car. 3-5 min is fine with gentle driving afterwards… Well whatever i live in the middle of nowhere with population of 8000 people and my catalic is off for more power and less restriction on exhust flow =)

  32. Anonymous - July 11, 2006

    Emmmmmm “Dinner Party”

  33. Matthew - July 14, 2006

    You non-nature guys really don’t get it do you? Or just find it unnecessary to understand:
    100 Sick As Gas Leaks Into Va. Dorm
    Friday, July 14, 2006
    SALEM, Va. – Carbon monoxide leaked into a college dormitory early Friday, killing a man and sickening more than 100 teenagers and adults attending summer programs at Roanoke College, the school said…
    …Carbon monoxide is a colorless, odorless and tasteless gas that can cause sickness or death. Leaks in buildings typically come from furnaces, heaters and other gasoline-powered equipment. “It’s essentially like drowning on the air,” Dowling said.
    http://home.peoplepc.com/psp/newsstory.asp?cat=breakingnews&id=20060714/44b716c0_3421_1334520060714230183579
    Sure the EPA has to show some concern.

  34. Nismo - July 14, 2006

    Yea…. nice back up there… that topic has notin to do with cars. Cars release fumes OUTSIDE not inside where the wind and air carries it away. You have to be an idiot to let your car warm up inside a closed garage. I dont think 2-4 min warm up when you first start the car didnt kill anybody.

  35. Anonymous - July 16, 2006

    Hello, I lived in Canada where the remote starter are quit popular in winter, I used to start my car 5 to 10 minutes when it was minus 30 C to warm it up I end up killing my ceder hedge after only one month. I stoped the warming period, if you are scare for you engine buy a block heater, who can be powered by clean energy. You are scare to start you engine, by a little electric 12 Volt pre-lube pump, I garantee you will heve your engine for 500 000 miles. Most of the car in the scrap yard are still running, we are consumer, and cars are top one. If you can’t stop consuming cars please at lease stop consuming natural resource, and polluting. Stop your car, no need for warm up, as long the oil pressure gage is up you are good to go.

  36. Reality check - November 25, 2006

    This is hysterical. So many people jumping at the opportunity to suggest technical advice based on pure speculation all in one place! Thank you all for the humor.

  37. sam - November 28, 2006

    I am suprised that no one has brought up the safety issue. I live in Edmonton Alberta Canada and it is currently -25 Celcius (-13 F), after it has warmed up from -29 degrees. Without the ability to defrost the windows, my breath eventually condenses onto the window and the visability out of the windows quickly becomes zero. For this, I beleive preheating is a necessity and not an merely an option.
    Maybe a better rule would be, don’t idle during the summer, and don’t idle during the winter once your temp gage reads normal in the winter?

  38. pam - December 6, 2006

    Well I live in Winnipeg, and I think a good solution to the problem posted above, regarding keeping the windows clear when it is really cold, is an interior car warmer on a timer. this will warm your car enough to make/keep the windows clear, and no idling is necessary to make this happen. The other night we left a party very late and the windows were frosted over on the outside AND the inside. Although scraping is an option on the outside, not so good on the inside, so a car warmer seems like the most environmentally friendly solution to me.

  39. GM - January 17, 2007

    I am sure we can make good arguments for either way.
    I think much of the warm up idling habit remains from the old days when cars did not have computerized engine manangement systems and would not always run well when cold. I preferred manual chokes for this reason. Never mind the fact that engines and oils have come a long way over time.
    I do know for a fact that my temp gauge moves to normal faster if I drive the car gently than if I idle it. This is because the engine is working rather than simply idling. The key is to try to drive it easy until the engine and oil warm. There is very little wear in a warmed engine and mostly all wear occurs when it is cold so I aim to get the engine warm as soon as possible. And driving accomplishes this.
    I assume that the converter warms up faster and starts to work (light off) faster if I drive the car and this lowers emissions. One would have to do test with emission equipment to see the difference in a driving cycle comparing idling 5 mins vs 30-60 secs idle time.
    I also know that idling a cold engine and being in the open loop longer will use more fuel than driving away gently after a minute or so. I will tend to warm the engine at least a minute when it is very cold – under 20F.

  40. Pat - January 19, 2007

    Hi Bret you have some good Info and a great point idling engines are bad. Taking things to the extreme is not so good either. Maybe some driving tips would be usefull in a futer write up. I know it’s not cool to drive in a calm fashion, but it saves fuel. You’ve seen the person in the car next to you race to the red light and then you arrive a few seconds later and sit there thinking to yourself what the heck was that show of speed in favor of? We are both going to be limmited and controlled by those same traffic lights and probably be next to each other at the next traffic light, and the one after that and so on. I’m driving conservatively and the other person is just mashing the gears and burning up fuel needlessly. After all difference between us will be when I go to fill up my gas tank I’ll be a few dollars richer when I leave the gas station. Oh yeah that person that was in such a hurry will have to buy new brakes sooner, and probably need service work allot sooner than I will. That person can also plan on replacing that vehicle after only few years, shock loading a drive train every day 30 times a day will pretty much destroy any any vehicle. I just wanted to share my thoughts on this.

  41. Bog - January 31, 2007

    My car seems to run smoothers and warms up faster in winter after i had to remove my catalic converter. Since the original cloged up, and I didnt feel like spending $200 on a new one. So $20 straight piper was more of a smarter buy for me. So now i dont have to warm up my car at all in winter time. Only 30sec-1min and its all better. It even has a slight bit of power at top end, since the gasses flow faster. So yea no more wasting $$$ on ideling lol =D

  42. CORY.,B - February 1, 2007

    OK I drive a 1969 pontiac GTO with a 350 small block the engine is rebuilt factory original so i was woundering my engine is cast iron as opposed to your aluminum engines alot of trucks are cast iron
    1.FACT=aluminum expands faster than cast iron so cast iron expands slower driving cold could crack it.
    2.FACT=your wasting your battery when you shut it off because it takes 25min average to get it back to where it was befor you started it.
    3.FACT=if your “so’ concerend about emissions bye a hybrid it will pay for itself if you care that much.
    4.FACT=forcing the oil pump to operate cold WILL wear it out because it is pushing thicker oil which it is already doing when you start it BUT when you drive it it +++ by 5%
    5.FACT=TIRE polution is worse than emissions

  43. Chuck - February 11, 2007

    Learn from my mistakes:
    And science. I live in PA, and the weather here is 9 degrees F. I have always thought a ‘warm up’ period wasn’t necessary, because of the better and nicer flowing engine oil 5w30 i have added to my 1993 audi 90. The car revs quicker and i get better mileage with this mobil one lower viscosity oil, too. However, what all of you fail, and i failed to see, is the DAMAGE that comes NOT from the engine, but the TRANSMISSION!.. Even though i had my transmission fully rebuilt only a year ago, and the guy promised me he put “fully synthetic mobile 1″ transmission fluid in. I drove in the morning one day without warming it up, and my car started to “hold in gear longer”, and shift rough. Went to audi dealor, and he told me, “that is normal, until the car warms up, for “emissions reasons”. I found out on forums that the transmission computer measures the temp of the tranny fluid, and if it is not hot enough, it will hold the shifts longer, thus using TONS more gas(so, instead of shifting at 35mph in OD, it holds it till 43!) and killing any “efficiency” one could have achieved by simply freaking shifting at the proper point!!! I had to rush to a job interview, again on a 9 degree day, and my tranny was SLIPPING and revving to 3000, yet barely moving the car from a light because i didn’t let it warm up. After i drove back, and the weather and tranny warmed up, it drove and shifted fine like it never had a problem or didn’t take out half my hair worrying about dealing with idiot bob the tranny guy and my warrantee!!.. So, listen you environment friendly geeks, you may be thinking you are “saving the environment” by “driving right away”, but you are destroying the moving parts of your auto at a RAPID RATE. Oh, and how, sorry. With the fluid cold, it SOLIDIFIES. And, so thusly, doesn’t get to parts it needs to LUBRICATE, and also pressures are off to make clutch plates apply, and therefore why my car super cold was SLIPPING. I have probably destroyed MANY a transmission and car by NOT following rules of warming up my vehicle first. My new idea, besides looking for an electrical gizmo to heat my cars oil at least, would be and has been successfull so far, is to wait, if any of you have a temp guage, and, if not, buy one. To wait until the guage starts to move. At that point, you have achieved approximately 100 degrees to the engine, and, like i have learned from these posts, will “drive easily”. I live where all i start out on is hills. So, I am going to have to try to circumvent them on cold days to further protect my investment from any more damage. And, yes, my car has a small 2.8 liter engine, is multi fuel injected, and would nearly pass an emission test without cats, but i keep em around in my garage for that magical, “one day a year” the law needs to see them. And the egr, which i may reconnect the vacuum tube to, to increase speed that my car heats up in the extreme cold, is like an internal “vacuum leak”. So, before, when i had it connected, going up a hill, my car couldn’t hold its speed above 35 mph up the hill, and at about 30 would have to ‘shift down” to a lower gear to use TONS of fuel to then get above 35 and then be back in fuel effiecint OD again. Now, with it disconnected, if i get the same good run at the hill at 50, my car has TONS more power, and stays above 35 or 30, and DOESN’T have to downshift and WASTE fuel(and thus, more pollute, the “environment”). So, if pollution controls do much more than take AWAY from the POWER that a car makes, then the car spends much less time in OD, thusly, it spends much more time HIGHER REVVING the vehicle, thusly putting a hole in the ozone QUICKER. If i had to wait in 40 min of traffic every day back and forth for my work it MIGHT even what i just said out. However, i get MUCH better power AND gas mileage by eliminating american “emissions”
    I want to create a system to allow the egr valve to work while warming up the car in the cold morning, but the egr valve only functions while OFF IDLE, not on, so this ALSO defeats the purpose of plugging that gas sucking/power robbing vacuum hose back in. Well, thank you for lettting me rant my science, i have spent numerous hours investigating and researching this, so if anyone needs any more data, just post it and i probably have looked it up or experienced it with my vehicles already. And, last thing environmentalists, quit wasting your time talking about this crap, and you should all get together and build a 300 hp hydrogen car we can all love and live with. Peace.
    ps. All of this doesn’t apply to a MANUAL tranny. They can only be warmed up by actual driving, and if i wasn’t soo lazy, would easily consider verses all the the bunk i have to go through to not have to worry why and when to shift(which, as U can see, i still freaking DO!)

  44. Juci - February 25, 2007

    Best solution, ride a bike. End of car problems. :P *LOL* It’s both cheaper and some people could lose the weight.

  45. cal - February 25, 2007

    Not warming up an engine during start up is completely ridiculous… If you immediately drive off after a cold start you are causing massive wear on your engine..WHY? because the OIL has not circulated everywhere. The oil also needs to be in operating temperature to be efficient. I dont care what anyone says, im warming up my car for every cold start, your wallet+car will thank you

  46. Jen - June 15, 2007

    At the very least. a cold catalytic converter will cause the car to put out more pollution than a hot one by not being hot enough to efficiently burn off excess hydrocarbons. There is a reason why you are told to drive your car around for 20 min before getting it smogged.

  47. Heidi - July 15, 2007

    How do the electric cars or hybreds shield the driver from electro magnetic radiation? I want to save the planet, but also would not like to bathe my internal organs with radiation while I drive for hours.
    Thanks

  48. evilpenguin - July 18, 2007

    Interesting thread. As to EMR, that is light, folks. Light and radio and, x-rays and gamma rays. I promise you that nothing in any EV is producing x rays or gamma rays. The voltages required for that are huge.
    Standing in direct sunlight complaining about the radiation you are getting from an electric car is like calling you neighbor during a hurricane to complain that his cat is breathing on your tree. You are constantly bathed in electromagnetic radiation. Bathed in it. And unless you spend time at the top of antenna towers or inside your microwave oven the natural sources dwarf the manmade ones.
    I realize that this will not be persuasive to someone convinced otherwise, but at the frequencies produced by most devices, the only possible effect is heat, not ionization. And by the inverse square law, even the heat is probably below detectability.
    The physical effect of photons is well understood. And that’s wha we are talking about here. Photons. The known harm of combustion gasses is vastly greater than even the possible harm from EMR. I’ll tell you what. I’ll stand in a closed garage with a running EV and you (a putative “you,” I’m not picking on anyone here) stand in a closed garage with a running gasoline car. Some one come check on us in three hours…

  49. K Caven - October 25, 2007

    I just find the resistance to this idea fascinating. I’ve visited European cities where they’ve all but eliminated air pollution with anti-idling laws. Personally, I’ve increased my gas mileage 30% by upshifting, kicking the idling habit, and more recently using MPG-caps. Sure, there are downsides to every action we take, but we have to weigh the inconveniences against more dire consequences. I’m willing to suffer a honk now and then if it means keeping that extra ton of CO2 out of the atmosphere – and my lungs. And the lungs of the kids at the stoplight.

    Hey, if anyone wants info to download or pass out, there are links on my blog – please come visit. http://homemadehybrid.blogspot.com

  50. Mike - November 11, 2007

    Okay, I drive a 1986 Lincoln Town Car. Not exactly new. Gas guzzler as it stands. Would the concensus be I should at least give the car 1 minute or so before driving off on a cold day? I’m sorta leaning toward that rationality for older cars at least.. and that several minutes (5+) for warm up is too much for anycar… in terms of wasting gas, pollution, etc.

  51. Boston Guy - December 2, 2007

    I’ll warm my car up for 10 minutes if there’s ice on the windshield or the outside temperature dips below 12 degrees F. That’s about 30 times a year on average. Otherwise, I’ll drive off either immediately or with less than a minute warm-up. That also depends on outside temperature. If you average it all out, my car still spends less than a minute warming up per cold start.

    I’ll also kill the engine when I know I’ll be idling for more than 5 minutes in traffic. I don’t think the greenies have much to complain about in my case.

    It won’t be long before lithium-based battery packs are good enough to allow fully electric vehicles to replace hybrids and even plug-in hybrids. If a battery pack can propel a vehicle over 150 miles at 70 MPH on a 5-minute quick-charge, who needs the added weight and expense of an engine and the components associated with it?

  52. Anonymous - February 24, 2008

    …since when do we worry about such microscopic issues…?

  53. Smartone! - January 24, 2009

    Block Heaters! :)