It’s that time of year again, and there are numerous articles out there about the subject of warming up a car when it’s cold outside before driving off. Thanks to changes in technology, oil, tolerances, fuel injection, electronic engine controls and manufacturer’s recommendations, the mantra for some time is to just drive off, gently for the first couple of minutes, as there’s supposedly nothing to be gained by letting an engine slowly warm up at idle speed. So I was a bit surprised to run into an article promoting a pre-drive warm up.
I happened to check in at Jalopnik the other day, and ran into Jason Torchinsky’s post promoting a pre-drive warm-up. Here’s his main point:
The reason has nothing to do with fuel or my latent desire to pollute your driveways — it has to do with oil. When your car has been sitting out overnight, all the lubricating oil that’s coating all of the crucial, moving bits of the car has settled down to the bottom of the oil pan. When the temperatures are really cold, not only is that oil not near the areas it needs to be, its viscosity — ability to flow — has been severely impaired by the cold. You’ve seen how differently, say, refrigerated maple syrup flows compared to hot syrup — the oil is the same way.
So, when you start that cold engine, it’s essentially running without lubrication. If you start up and immediately put a load on the engine, things could get damaged. It’s just not ready to go. Take a minute or two to get that oil pumping around before putting any load on the engine, and your pistons and camshafts and turbos and other spinning, moving bits will be much, much happier.
Now, you don’t need to idle for a half hour, but a few minutes just to get the fluids a bit thawed out is not a bad idea at all. Have a stick shift? Have you ever felt how sluggish the stick feels on a really cold morning? Think about all the components inside that housing, and how they’re doing. Let the car have a moment to wake up and spread some warmth and fluids around.
Frankly, there’s no harm in a short warm up, but his point about the oil and lack of lubrication is not really accurate. Oil pressure builds almost instantaneously, and oil is essentially non-compressible, which means that the positive displacement oil pump will pump the same amount of oil regardless of how cold it is. And if one is using the appropriate oil, it’s not likely going to have the consistency of refrigerated maple syrup. And for what it’s worth, cold oil has better film strength than warm oil.
I’ve been long convinced that driving off reasonably gently is no different to a cold engine than sitting idling. And it will warm up the engine faster. And the transmission isn’t going to warm up while sitting idling anyway, unlike Torchinsky claims. But when it comes to issues like this, everyone has an opinion. What’s yours?
This is the first winter I’ve had with this particular car. I just let it run a minute and then drive gently. I’m in town anyway, no real need to go over 20.
My Buick had the piston slap so I’d usually wait until that calmed down a bit.
Peterborough Ontario Canada = -35c . Cold start & drive will not rear its ugly self untill the warranty is over. If your car is a keeper & not an appliance , let it warm up. Seeing out of the car is a good idea , while texting, eating, drinking & all the other stuff people should not be doing while in control . not!
I start my Versa, let it fast idle while I buckle up, put my drink in the cupholder, tune the radio. When the fast idle slows down, then I take it easy until I feel heat coming out of the defroster. By then I’m merging onto the highway anyhow. It takes about ten minutes before solid, genuine heat starts flowing.
That picture looks to me like someone left their windows down and a blizzard filled it.
I live in Houghton, MI. Very high latitude. Frequent – F ° startups in January. Park in carport. 2014 Fiesta ST and 1993 Saab 900. Start them rolling easy as soon as I start up and buckle in. Like Paul said, it helps warm the motor up faster, and I’m making progress and not wasting fuel at idle. My SAAB owner’s manual specifies to vary RPM and load at cold temperatures.
Suburban Chicago. Cars overnight in the driveway — too many hockey goals, drum sets, bicycles, etc in the garage.
Go out and start the car. Come back inside, make a cup of coffee. Go back out, get in car, drive away. Probably a two min. warmup.
BTW I back my car in every night. Much safer when leaving in the morning, esp this time of year when its still dark or near dark. In the summer months when the days are longer the danger shifts to kids riding their bikes down the sidewalk. Havent accidentally backed over one of my neighbors while walking their dog yet!
Many safety-conscious employers in the construction, petroleum, and other industries require their employees to back into parking spaces when at work.
Depending on the outside temp, I usually give my car a minute or two minutes to warm up. If it’s freezing outside, below 35 degrees, I may give it more time.
On a cold morning I will let the car run a few minutes before heading off….especially if the windows are covered in frost…..Starting up after a snowstorm, I often let it warm up for 15-20 minutes while I remove the snow from the car…..I like to get some heat on the windows before I start scraping ice buildup……I put a crack in the windshield of my Dad’s 73 Suburban many years ago scraping ice off the windshield before the defroster had a chance to thaw it out…..so ever since then, I give the car a chance to warm up before scraping the windows
My 87 Caprice Estate I owned about 7 years ago would experience valve knock if I turned her on and drove off even in the Southern Tier summers, but it was worse in the cold. So yes, I let her warm up a few minutes and if I had to enter a 55 zone I would ease out and work my way up to 55-60 over 1-2 miles. Sometimes I would pull over to let her warm up some more.
My 95 Voyager I drove until a few years ago she experienced -21F to 99F and I warmed her up, more so in her later years. When it was -21F the engine raced for a good 5 minutes and even then she would not shift out of first without a few more minutes of warm up. I even had shifting problems at 30F if I did not let her warm up enough. Since my folk’s house is near a 55 zone I would spend extra time letting her warm up since I can feel it when she did not want to get above 40 or so. Having a rental house in a 30 zone near a stop sign was nice since I could do more warming up and driving at the same time. When I drove her across the country I would often drive about five minutes before hopping on the Interstate unless it was above 60. I got really good at figuring out her responses based upon the temperature.
My 03 Caravan acts a bit like my Voyager, but he has less severe reactions. When Portland got down to the teens last year I certainly felt some hard shifting until the engine warmed up. Even in the Summer I will turn on the engine, buckle my safety belt, turn on the headlights, and drive off. That gives me the chance to listen to the engine before driving off so yes I have always have let my vehicles warm up before driving, even if just a wee bit.
I remember my folk’s turn of the century Malibu rental car hated it when the Orlando area got down to near freezing since there were squealing belts, the steering was stiff, and the car was sluggish in general. That 2012 Express I drove did not care about being driven right off the bat at 20F or at least I did not care and my shivering passengers could warm up faster.
Course if there is ice and/or snow on my vehicle to clean off I am always going to turn on the engine since I have a good excuse to waste gas and let the engine warm up some more.
The owners manual for my 1994 W124 four cylinder petrol engine explicitly states not idle upon starting your car but move off immediately upon engaging the gear box.
I’m in the Far East with temperature between 6 to 38 degrees C, so Mercedes’s advice is to prevent overheating rather than concern for engine lubrication.
I’ve a one kilometre 45 degree hilly road to climb every time I leave home. I’m gentle on the gas for this section and happy to let the car climb up the gears at the recommended RPM.
My two cars in the garage (insulated) need only a couple of minutes to warm up as the interior of the garage is about ten degrees warmer than outdoors.
My 85 Grand Marquis is in the driveway and its 351 V8 needs about 4 minutes of warmup if it’s about -20C or so. There is no need to scrape any windows if I cover the glass with an old blanket, so it’s matter of pulling it off, turning on the defroster and driving away gently at first. by then I’m getting heat and I about three blocks the interior is pretty toasty.
“And the transmission isn’t going to warm up while sitting idling anyway”
This is incorrect.
The only way a running engine does not add heat to a transmission is if you have a manual transmission and you are holding the clutch in. As long as the transmission is bolted to the back of the crankshaft, and the crankshaft is turning, there is mechanical energy transmitted to the transmission and that adds heat to the fluid in the transmission.
My general rule is no less than two, but no more than five minutes of idle. That’s considering it’s less than thirty degrees outside. I do this moreso in my Subaru than my truck because the Subaru’s boxer engine is a little… Wonky, on cold mornings. The main thing with having an EJ is that they really don’t like cold starts. I’ve never been able to figure that out. In the truck I kind have to worry less with it havin’ the honkin’ 4.7L Triton V8, but I barely ever use the truck for daily driving, so it avoids most cold mornings.
In a perfect world, with a perfect car, and perfect operator, the warmup procedure would involve heating the coolant up *gradually* to 180 degrees F prior to cranking over the engine. Also, there would be a means provided for inducing 45 psi oil pressure in the engine prior to cranking over the engine. This would be done via electric oil pumps.
Actually there is a pretty simple system for bringing up the oil pressure which you can retrofit to an engine. It connects to a pressurized oil passage of the engine. The easiest place to plumb it would probably be wherever an oil pressure sensor would attach.
The system uses a bottle with a checkvalve which is pressurized from the oil pump while the engine is running. When shut off, the bottle retains pressurized oil. Just before starting the engine, you activate a solenoid which bypasses the checkvalve, sending pressurized oil the other way into the oil passages of the engine.
There are also ways to warm the coolant prior to starting the engine. An electric block heater is an obvious one. I have also installed an Espar Hydronic coolant heater under the hood of my pickup truck. This is a self-contained diesel-fired heater which has a air-to-fluid heat exchanger and an electric pump to circulate the coolant through it. (There is also a gasoline-fired version.)
I installed it primarily so I wouldn’t need to worry about finding a place to plug my electric block heater in when it’s really cold and I’m away from home. I also activate it on REALLY cold mornings (like today, -21C when I left for work!) even when my truck has been plugged in, to warm it up a bit before I leave and get at least a little heat in the cab.
That is AWESOME! I am seriously going to look in to those mods for my vehicles. I have never heard of a gasoline powered block heater before. That pressurized oil bottle you are talking about sounds suspiciously like an accumulator used in power hydraulic systems. It never occurred to me that one could be adapted for use in a lubrication system. That is a GENIUS idea!
From the Nordic perspective it is absolutely hilarious to read about someone in Florida warming up their engine by idling when the temp is below 50 F (10 C?). This is a juicy topic, so lets have some opinions… If working the cold engine would be such a hazard, surely failed engines would more common in northern climates vs. the south? That seems to not be the case, even with the complicated and small turbocharged engines, esp. diesels. I would imagine that the impossibly high pressure injectors or the cheaply manufactured miniature turbos would be the first components to break, and they sometimes do, but learning from the internet, they seem to fail also in southern Europe. Suggested reasons include (overstressing cheap components…) bad fuel, dirty oil… All car manufacturers do extreme arctic testing – in our user manuals the recommendation is to avoid unnecessary idling with cold engine. The “experts” say that the oil gets contaminated and moderate loading is good from the lubrication viewpoint -idling cold engine would be worse. Above someone suggested that the transmission warms up during idling – but isn’t the point of modern manual transmission lubricants to reduce friction as much as possible? There is some friction and heat, but is the amount meaningful?
A warm car is of course better in every respect; comfort, emissions, engine wear etc., but is idling the answer? What is the overall impact on mechanicals is not clear, but fuel is wasted, especially because the engine is cold. The catalyst has not reached the working temperature, the engine runs rich… so the emissions are high and you release them on your own doorstep. Of course, it used to be much worse before with the badly adjusted carburetors etc., and especially outside the US, as the emission laws used to be less strict e.g. in Europe. Mmm, the smell of winter in the 80’s… cold air mixed with delicious hydrocarbons…
The nordic smartass rant continues: in our corner of the world practically all cars have some sort of electric block heater, usually with an outlet in the passenger footwell so that you can use a small electric heaters to warm up the interior. With the block heater you reduce the fuel consumption and cold emissions, and with the high fuel prices it even makes sense to pay for the extra equipment. Auxiliary diesel/gas heaters are also common, especially with diesels. It used to be that diesels were notoriously difficult to start in really cold conditions, and if you didn’t have an electric outlet nearby… Hence the webasto/ebersprächer etc. Nowadays with the modern oils the cranking up of the engine is not the major issue, it is more about the passenger comfort: The diesels have less waste heat which means that vans and wagons warm up slowly. Some cars have electric heating elements built in the heater (that turn on when the car runs). Is the seat cold? I would suggest long underpants… And seat heaters are nice to have. However, with the auxiliary heaters and increased amount of electrics in general, you start to get issues with electricity – cold batteries charge poorly in winter. Which leads us to the third use for the block heater wiring: it is becoming common to install a battery charger, so that while the engine/interior is warming up, the battery is charged as well. They’ve also started to sell small heating mats for batteries, reasoning being that you save money by increasing the service life of the battery by keeping it warmer and topped up. Not sure if it really works in practice.
My diesel Polo is currently waiting at the office car park, hooked up. The outlet has a timer, so that it turns on when you want to and stays on for max 2 hrs (but there are also solutions with thermostats or remotes). It is not very cold today, but some snow always gets in, and eventually it melts and then fogs up the windows, so it is useful to dry the interior every now and then. I park on the street in Helsinki, so no electricity available in the mornings. Idling is forbidden by the law if the temperature is above -20 C, but most people tend start the car first if they need to clean the windows. Me too, mostly by habit, as the engine only warms up much later – by driving. On the other hand, the seat heater gets a head start and the heated mirrors and rear window might thaw a little… Brush brush brush, scrape scrape scrape. Brrr. Now where was that article, the one with the pictures of convertibles with the palm trees in the background?
On a side note, I think it would be awesome if VW brought the Polo to the States. Especially the GTi and TDi. Other people, the young enthusiast crowd, have been clamoring for the current Scirocco. Sadly, it isn’t likely to happen in either case.
Very good post from someone well acquainted with cold weather. Interesting to note that Muir was probably dead before synthetic oil became common. Also interesting to note that idling is not legal in Helsinki and SAAB says not to do it. I would think that would not be so if research had not been done.
I don’t really have a dog in this hunt but do believe that heading out gently and immediately won’t hurt your vehicle. I also think that cold idling will. I realize that not being an engineer and living in the south compromise or at least detract from any legitimacy my opinion might have. I think Finland is pretty far north and pretty cold. What you say about illegal idling and SAAB recommendations should lend legitimacy to your statements and cause commenters to read them twice before regurgitating things that were true 30-40 years ago. BTW my cars normally last over 300k miles and probably my actions regarding this subject have little to do with that. Who knows?
My $.02. I’m done.
I do wonder what these “no idling” regulations and recommendations expect that you do when the car is iced over. Scrape all the windows before starting the car? The hell with that. I’m going to let the defrosters do as much work as possible!
Ice and snow make a difference but you can idle for a long time and not get very warm. You can have heat in 2-3 slow miles.
Making idling illegal is dumb but knowing it made a point. I have been surprised at the strident opinions I have heard in this thread (on three sites). It does bother me when one tries to make the opposing pov seem stupid. I simply think that the opinion that one must idle more than a minute before starting has it’s roots in the days of poor lubrication and fuel management.
YMMV but there are a lot of people here who are certain they are right and absolutely opposed on the matter
I agree on being surprised at the level of passion on this point. I remarked to a friend yesterday that this topic has generated as much heat as any discussion about Obama or Bush. 🙂
I was told that idling the engine for any amount of time before you put the car into motion is not good for the engine or the transmission. I was never told why it was not a good thing to do, just that it wasn’t good for the car. Is it really a bad thing to do, or not?
Seems like you can choose your side and have lots of folks backing you up. Since I have driven FI cars I have not. If I had to clean windows it only took a minute and I really don’t remember idling while I was cleaning them. I may have. Even with carbed cars I would get going asap.
I figure you can idle at 1500 rpm for several minutes and still have very little heat or you can drive at 1500-2000 for about two and get heat. Seems to be less cold engine operation by a bunch. I sure do know that there will be a batch of folks who disagree with this. Chances are they learned it several years ago or learned from someone who did.
I would suggest anyone try both ways and see what happens. Whatever you decide you will obviously find many strident supporters here and on a couple other sites. There will also be a plethora of antagonists who will suggest you are a couple cards short of a full deck.
Absolutely. I would never consider putting a load on a cold engine. Cold metal is weak and brittle, and cold oil does not lubricate very well. I am a former private pilot, and one of the things that was drilled into me but good at flight school was never run a cold engine above idle. John Muir, who wrote the VW “idiot book” estimated that your engine would last about 30% longer if you did a proper warm up. And he had an engineering degree.
All this crap about not needing to warm up your engine comes from every car enthusiasts worst enemy. The EPA. They don’t want you to warm up your engine for several reasons. It burns a tiny bit more gas, it makes a tiny bit more pollution, it causes your engine to wear out faster, and when their engine wears out, many people buy a new car, which in theory should make less pollution than the older one, and it helps the auto industry, which along with big oil and the govt, are all in the same bed.
So basically it is all political. Engines need to be warmed up just as much now as they did 50 years ago. And this comes from someone who has put over 300,000 miles on engines that usually wear out in under 200,000 miles.
EXACTLY!
I am beginning to wonder if this thread was inspired by a discussion on another thread about when and why the “cold” light disappeared from cars’ dashboards after the first gas crisis. Clearly, those who are promoting zero warmup due to superior modern lubricants do not fully understand mechanical devices, lubrication, metal properties, and the concept of clearances.
This may all be true, but there needs to be some context. What exactly is going to wear out faster, and will that outpace the wear on rest of the engine or even the car itself? And even when it’s 80 degrees out your engine needs several minutes to reach operating temperature. Yet I’ve never heard of anybody giving that consideration in the summer.
Bottom line for me is that I’m not going to worry about it. Doing so would require me to let my cars warm up for 5-10 minutes twice a day. Not only does that add up to a significant amount of gas over an entire winter, it’s simply not practical. I have a feeling that by the time the claimed increased wear and tear has an effect the car will have little to no value left.
By that line of thought I will argue that seat belts, air bags, and antilock brakes are not worth my time.
Both issues(warm up and collision protection) are an attempt to deal with probability of an event. The event is death in an accident or catastrophic engine failure during one’s ownership.
There are three kinds of accidents. One that is so minor that airbags and seatbelts serve no purpose…one that is so deadly that seatbelts and airbags are of no help…and one that is between the two extremes in which the air bags and seatbelts actually save my life.
I am middle aged and have been driving for decades. In that time I have been in a few car accidents, all of which were in the days before seatbelt laws, before airbags, and before anti lock brakes. A couple were even in cars that did not even have seatbelts. I never sustained a single injury.
In the driving years I have left, the likelihood of me having an accident that is of the type in which seatbelts and airbags will actually save my life is very small and if it does happen, most likely I will be so old that they wouldn’t be saving much anyway.
So I don’t see the point.
My point is there was no context as to what exactly will wear out and at what approximate mileage and nobody worries about not warming up to operating temperature in the summer.
Your accident analogy is a faulty one on many levels. A seat belt will last longer if I only handle it with lambskin gloves and wear sweats.
As I stated further above I do let my vehicles warm up for a minute or two when it’s really cold. But it’s not practical to always let them warm up for 5-10 minutes. A seat belt, on the other hand, only takes about 2 seconds to put on.
I typically replace my vehicles when they are around 100K miles. I have seen little to no evidence that my quick warmups will cause me any problems during that time. If I planned on keeping a car to 250K+, then maybe I’d take it a bit more seriously.
Maybe some day I’ll have a car with less than 200,000 miles on it when I buy it……
Dreams , they’re nice to have .
-Nate
I let the car warm up for about 10-15 minutes every morning, and I think I have a good reason separate from all those mentioned: I only drive it about 1 mile to the train station before I park it again for 9-10 hours. If I just hopped in and drove off, the engine would never fully heat up. When I come home, I do the same thing, or more often just drive around the block a few times.
Sean, sounds like you need a bicycle!
Walking is better!
Fuuuuuuuuuuuuuuuuuuck that! LOL
Nothing against bicycling, or walking – I enjoy both, but not at 5:00AM when it’s 20-something degrees out. I Google Mapped it and it’s actually 2.5 miles, or a 39-minute walk, and just thinking about waking up that much earlier gives me a migraine. It’s hard enough as it is!
I don’t actually take the car all that often, though. I can get a ride most days and then I take the bus home (which I would do in the morning, but they don’t run that early).
For all other trips, I’ll either just get in and drive off or let it warm up for ~5 minutes if it’s seriously cold (<20F). It's a 17-year old car with 150k miles and I don't use synthetic oil. If it was newer I'd never bother with that.
I hear ya. Seems to be a big push around Minnesota for bike lanes and paths. Even as a cyclist myself, no way would I want to be biking around all winter. Because #1, it’s miserably cold and #2, riding in the dark near traffic on ice and snow is a death wish.
Regardless of whether the outside temperature is -1c or -35c, my procedures are the same:
If there’s snow, then i start the engine and then let it idle while i clear the snow and ice off the car. So the warm-up is different whether there is 2 inches or 2 feet of snow on the car.
If there isn’t any snow i start the engine, wait for the idle to stabilize and then off i go, trying not to rev it over 3k for a few miles.
Have had only 2 cars thus far, both V8 gasoline engines. Never plugged in and usually sitting in winter for a month or more between starts.
I let my car warm up on colder days (-15C or below). Mostly this is because of the time it takes to scrape the windshield when it is so cold. That frost on really cold days is like glue.
Last week was the first time I plugged in the block heaters on both of our vehicles. We had 5 days in a row where the daytime temperature struggled to break -20C and overnight was touching -25C. It’ll get colder in the next few weeks. I did notice a difference in how easily the vehicles started. The oil was up to proper temperature and the engine and transmission worked much better.
For me, it’s not so much about whether damage is being done to the engine or not. I just take it easy until it reaches normal operating temperature. It’s mostly how everything else is not working properly. If the windshield is cold, the washer fluid (even the -45C stuff) freezes on the windshield on the highway, so it is useless. The steering wheel is stiff and even squeaks. The shifter and pedals are stiff. The side windows won’t roll down. A few minutes of warm-up lessens the time I have to deal with all of these issues on my commute.
Hell, on my last car, the touchscreen wouldn’t work and the backup camera was mostly just scan lines. Not to mention that it was a manual and it felt like I was shifting through caramel.
Oh, and it allows the heated seats to warm up. 🙂
I lived in the mid Hudson Valley (sixty miles north of NYC) for 8 years. If the temperature got below 40, I would let the car warm up. If it snowed, the car would be toasty inside once I got the snow shoveled and the windshield clear.
The warm up process was the reason why I got 200k miles out of the vehicle (2005 Ford Escape 4WD) with no engine or drive train issues.
The only issue was the tin worm. New York is a SALT state!! But that’s another story.
I didn’t even bother to let my street-parked, ’64 Dart or my ’60 Lark idle more than a minute or two in Chicago winters when it was my daily driver — why would I let a modern,
fuel injected, auto start-stop, (i.e. well engineered) engine do more than I did the slant-six or v-8 in those cars? My 240D needed to be plugged in to start, so it was always warm when the weather was less than 25 degrees anyway.
If you change your oil in 5000 mile increments, you’re not going to get engine wear.
I believe in the miracles of modern oil additives (but I’d also put the ZDDP back into
the oil for my older cars). The rest of the car will still be -10 deg. F anyway .. so drive immediately and chatter away.
Ooh. That right there is a great forum topic for this website. A lot of classic car people increase the concentrations of ZDDP in their engine oils.
The proper thing to do is buy the appropriate oil, adding ZDDP actual causes problems with oil as it is a carefully balanced mixture and depending on the oil in question its film strength is reduced slightly or significantly.
Yes you can have too much ZDDP just as well as not enough. It’s difficult to find an oil with the adequate concentration of ZDDP though, especially in Canada where we don’t have as good selection of oils as in the US.
I run Rotella 15W40 in my Chryslers as well as my Cummins. The latest formulation (CJ I think) has lower ZDDP levels than previous though, so I add 1/4 bottle of Lucas TB ZInc+ additive to my Chryslers (but not the truck). I researched this and determined that this should provide concentration in the ideal range. A whole bottle of the Lucas additive would provide way too much ZDDP.
In my truck I add a can of Molyslip when I change my oil in the fall, for added cold-start protection in the winter months. Another long-time Cummins owner recommended it to me years ago.
Well I haven’t looked into the formulation of the Rotella sold in Canada and if it differs from the formulation sold in the US but the 15-40 and 5-40 synthetic we get in the US is more than sufficient for an old flat tappet cam and you certainly should not add even a drop of zinc additive to it.
The problem is not really the too much ZDDP but not having the right balance of other chemicals. There are oils out there with 2x the needed ZDDP that have high film strength but they were formulated from the get go for that.
For you Cummins switch to the Rotella 5-40 for the winter. It makes a huge difference in cold start even down here where it doesn’t get that cold.
Paul, I agree that Torchinsky at Jalopnik propogates myth occasionally, but that said, I enjoy that site very much.
With regard to the tech matter, no, I don’t let my engine “warm up” I live in SoCal after all, and my engine might chill to temps below 40F perhaps 2 or 3 times a year, so really an issue.
Lastly, electronic fuel injection has so allowed engines to run cold so much better than carburetors ever could that it is often difficult to detect an engine is cold save for a fast idle. Miracle!
Sorry Paul but you’ve got it wrong. Yes a oil pump is a positive displacement pump but it has a relief valve that limits pressure so a large percentage of the oil can be dumped back into the pan if the right viscosity is not used for the low temp. Again if the right viscosity is not used it can take a significant amount of time before the oil reaches the valve train. Even the 5w-x oil can take a noticeable amount of time before it reaches the valve train if it is truly cold out.
You should let your engine idle for a minute or two before heading out even on a modern vehicle. More than that is not necessary. It is a good idea to take it easy until the temp gauge shows that it is in the normal range at least on the few cars that still have a real temp gauge and not an idiot gauge.
if the right viscosity is not used for the low temp. Everything has an exception. Did I recommend using the wrong viscosity oil somewhere? No; I specifically said using the right viscosity oil is important.
So I’m not “wrong”; you’re just determined to find/create a loophole in order so that you can say I’m wrong, because I know how much that means to you.
There’s simply no technical or objective argument about idling a cold engine for a few minutes before gently driving off that I’m willing to accept is really valid or needed. If there is any negative impact from the cold start, it will be essentially the same at high idle as during a gentle drive. And the manufacturers, who have warranties and reputations to care about, seem to all feel the same way. But what do they know?
But as I said, idle away….
No you are the one that likes to stir the pot. Your statement
“Oil pressure builds almost instantaneously, and oil is essentially non-compressible, which means that the positive displacement oil pump will pump the same amount of oil regardless of how cold it is.”
Is flat out wrong.
Oil pumps have a pressure relief valve built into them for a reason and that is to prevent the oil filter from blowing apart or the oil pump drive from breaking on start up in cold weather.
The oil light may go off immediately but that does not mean that oil is flowing to all parts of the engine, just that there is pressure in the main gallery where the oil pressure sender is located. On most engines is very near where the oil pump feeds the main gallery. That by no means indicates that oil has flowed to all of the components that need lubrication.
You’ll note that I said let it idle for a minute or two. That is to ensure that oil has reached all of the lubricated points.
Many people in colder climates use the wrong viscosity on a regular basis. Manufacturers have largely gone to a “one size fits all” approach but that doesn’t mean that using a 5-x oil is the best for engine longevity if you’ll see temps below zero. In areas where it gets real cold 0-xx oils have been available for decades and those in the know use them in the winter despite what the manual may say.
Take a look at the link to the motor oil 101 article on Bob is the OIl guy that was provided above.
I nevere let my Jetta idle to warm up. Its parked in a detached garage so no need to scrape windows (never understood why some would rather waste time scraping windows everyday than cleaning out the crap in their garage they never use).I figure the 1-2 minutes it takes to get from my garage to a major arterial street is enough. I never turn on the supplementary cabin heater due to the diesel either, seat warmers do the job just fine.
The “take it easy” part is not possible for me. Because of where I live, right next top a main arterial street, I have to floor it to merge into traffic most of the time. I live in Phoenix, AZ, so warm up does not take that long, even inn the winter. But even in the summer I will let a car run 5 minutes before taking off. Just because it is 90 degrees outside does not mean the engine is warm. Engines operate at a much higher temperature than that. It also allows the oil to circulate throughout the engine. My older cars take quite a bit longer to warm up than the newer one. They are carbureted, jetted on the rich side, and they have far more efficient cooling systems. My ’64 Ford can be left idling all day in 110 degree temps, and the temp gauge will barely move. Newer cars run hotter and with higher pressure in the cooling system. They have higher temp thermostats in them. Higher operating temp is just another way to control emissions.
If you want to wear out you engine faster just for the sake of convenience, it’s your car. I need to get every mile I can out of mine. I also change my oil every 3000 miles, and would do so with a brand new car. While oil quality has improved, newer engines operate under a lot more stress than older ones do, so it still comes out about the same. Plus, being a mechanic, I just cannot bring myself to abuse anything mechanical.
If it’s in the garage in winter I drive right off, I just keep the rpm’s low and go easy on the gas until the temp gauge approaches normal. If I need to run it first to clears glass that’s the only time it warms up before I go. That’s pretty standard these days, the old carb Chevy needed about 5 minutes or more if really cold to warm up so it would not stall out, but with fuel injection runs the car runs good right away. Modern oil also works better when cold. Old cars still need a little warm up time.
Here’s a semi-related question for all the Canadians and other cold weather experts:
How cold does it have to be for you guys to use a block heater? My car originally came from somewhere way upstate New York and has one, but I’ve never even thought about using it until just now. I live in Long Island, where it gets down to the teens (Fahrenheit) at absolute worst, and the car never had any trouble starting… but you can tell it would rather stay sleeping on the really cold days. Obviously I’d never have to worry about the engine actually freezing, but is it worth it for me to plug it in on those days just to make starting a little easier, or is that a total waste of time?
A block heater is actually a good idea all the way up into the 50s (F) if you really want to take care of your engine. Something else you can do that serves two purposes, is to put the transmission in drive if you have an automatic, with the parking brake on, while warming up the engine. That provides just enough of a load on the engine to warm it up faster without damaging it, and also warms up the transmission.
While most of what I post on here is just my opinion, I consider the benefits of warming up your engine, whether it is new or old, to be proven fact. It is absolutely required for an aircraft engine, and the only real difference between an aircraft engine (besides the price) is that car engines are liquid cooled, while most aircraft engines are air cooled. This makes no difference when first started. They are both cold, and cold metal wears faster and is more prone to break. There is also the danger of thermal shock. Placing a load on a cold engine can cause it to warm up too fast, the metal expands too fast, and cracks. I warm up my Fairlane and Pinto for 10 full minutes before taking off if they have sat overnight. My V8 powered S-10 has both coolant and oil temp gauges, and I will not take off in it until; both reach a certain point, just like in an aircraft.
I consider warming up an engine just as important as maintenance. GM has extended their recommended oil change intervals out to 7500 miles. If I had a brand new car/truck, I would still change the oil every 3000 miles.
My sister and brother in law bought a new ’99 S-10, never warmed it up, never maintained it properly, and the engine crapped out at 115,000 miles. I bought my ’01 Malibu with 98,000 miles on it, and it was obvious it had not been properly maintained. I started over maintaining it, properly warming it up, and driving at a reasonable speed. It now has 202,000 miles on it, and is still running strong. The front end is starting to wear, and it has developed a shimmy above 65. I plan to drive it from Phoenix, AZ to Portland, OR and back next month, at 55 mph. Then I will start looking for a replacement. I prefer to do my racing on a track.
My previous car, which was 16 y.o. and I’d owned and driven 14 1/2 years, had a 2.0 and a 5-speed stick. Virtually all my co-workers idle their cars 10-15 minutes or more – some a whole half hour, to melt snow and ice because they lack a snow brush or ice scraper, or because they went to get into a toasty warm car. Will say I sometimes take time to brush off the snow or scrape off ice on other peoples cars. Anyway, I’ve been in the habit of driving off in my car within a minute or two of start-up. Must point out that I’ve run full synthetic oil. And, when I traded in the old car on my first-ever new car, it was running fine at 227K miles. That’s an American made car, by the way, a Dodge.
What I got installed on my new car is an engine block heater, which I’m certainly making use of in this rather frigid winter. So I continue to let the new car idle for no more than a minute or two and it seem to do fine. A couple hours before I go to work I plug it in inside my garage. At work, I plug it in at least 2-3 hours or more before I get off work. Even though I’m in Ohio where it doesn’t always get this cold, it seemed like a worthwhile investment. Oh, and what I failed to mention is that with both cars, I drive away gently after start-up. Some of my commuting is on city streets and the rest at no more than 55mph. So the engine is rarely highly stressed. With my former car as with this one, I’m rarely above 2000RPM.
I don’t mind warming up a car engine for up to 10 minutes, however long it takes to warm up the car and defrost the windows enough to safely drive the car..
Once it drops below 50 degrees Mr. Pansy here in Houston and the little Princess need a heated car for our 30 minute ride to school. I hate cold.
My (retired) Trooper sounds like a diesel on cold mornings….the Sube considerably more calm.
When it’s over 40, no, I just get in and go, but when it’s below 40, I let it get at least a little warm inside. I leave the vents set to blow hot air on the steering wheel, so it’s not like I’m holding something made of ice. My next car will have a heated one, as a cold wheel kills my hands. When it’s sub zero, it runs as long as the remote start lets it go for, about 12 minutes, and I usually hit it again as I’m leaving work, so it’s actually kind of hot inside before the door is opened. I don’t seem to be able to tolerate cold like I used to be.
” I leave the vents set to blow hot air on the steering wheel, so it’s not like I’m holding something made of ice. ”
I discovered a nifty trick to deal with this 40 years ago : cheap white cotton gloves , the ones with plastic ‘ dots ‘ on the inside of the fingers & palms ~ they keep your hands warm but not sweaty and breathe well too , the plastic dots make the grip secure ,a good thing if you’ve ever had a steering wheel slip in your gloved hands .
They’re washable too , just toss ’em in with your jeans or work clothes once or twice a year .
I love ’em as I like to drive with the windows open down to about 37* F and my hands get really cold and painful otherwise .
-Nate
Great discussion. One point, the oil pump has a pressure relief valve so when cold that pressure is bypassing a lot of oil out the relief back into the pan. But thick oil is flowing to the necessary places, just not as much.
My method is to first start the engine then put on seat belt, tune radio, plug in phone etc, before driving off. A couple of minutes at most but enough. In cold northeast Illinois when it snows or is icy I start the car then clean the snow off and scrape the windows while the engine warms up. This is mostly for comfort and being able to see, not to warm up the oil. I keep my cars a long time and have never had an oil related engine failure so it works for me.
I pulled the oil pan off the engine out of my ’69 Chevy C/10 to -day for cleaning and it’s whistle clean inside ~ those short warm ups and blistering hot oil & filter changes cleaned it up nicely ! .
-Nate