Debate: Proper engine warm-up procedure in the winter.

"Stang70Fastback" (Stang70Fastback) 01/08/2014 at 11:16 • Filed to: None

2

100

With this recent cold snap (sorry, I mean Polar Vortex) having brought colder temperatures to much of the country, I have seen renewed debates online about the proper way to warm-up your vehicle in cold weather. There appear to be two sides to this debate - both of which make reasonable arguments:

1. Let the car warm up BEFORE driving. The reason being that engine oil becomes thick at cold temperatures and does not do a good job of lubricating the engine. Therefore driving the vehicle in this state creates extra heat, friction and wear-and-tear on engine components. In addition, other systems can be affected. For example, it is possible to blow out a power steering line if you drive off immediately in particularly cold weather without allowing the system to warm up.

2. Give the car 15-30 seconds for oil to start flowing, then DRIVE the car to help it warm up more quickly. Of course this does not mean you should go WOT and pin the tachometer. However, gentle driving helps that thick oil flow better, and gets it warmed up much more quickly. The argument here being that the increase in wear-and-tear you experience by revving an engine with cold oil is more than offset by the fact that the oil gets up to temperature faster, and therefore starts protecting the engine much more quickly.

Both arguments make sense. My quick Googling always seems to find more people favoring the second argument. I even went through the User Manual in my car (1998 Subaru Outback) and the only snippets of information I found are the following:

In the section describing the engine temperature gauge:
"We recommend that you drive moderately until the pointer of the temperature gauge reaches near the middle of the range. Engine operation is optimum with the engine coolant at this temperature range and high revving operation when the engine is not warmed up enough should be avoided."

In the section describing the steps for starting the vehicle:
6. Confirm that all warning and indicator lights have gone out after the engine has started. The fuel injection system automatically lowers the idle speed as the engine warms up. While the engine is warming up, make sure that the selector lever is at the "P" or "N" position and that the parking brake is applied

In the section giving tips for winter driving:
"While warming up the vehicle before driving, check that the accelerator pedal, brake pedal, and all other controls operate smoothly. Clear away ice and snow that has accumulated under the fenders to avoid making steering difficult. During severe winter driving, stop when and where it is safe to do so and check under the fenders periodically."

The user manual at no point actually references a specific time-frame for which you should allow the vehicle to warm up (or a certain temperature gauge reading), nor does it explicitly state "let the vehicle warm up before driving." It only states things you should do (do not leave the vehicle in gear, and, in the winter, check that the controls all work) while the vehicle warms up.

I am interested in starting a debate on this subject and seeing what the Jalop community thinks, and how they warm up their own vehicles!

EDIT: I suppose I should add that my personal view leans towards the second option. Also, in this debate we should exclude warming up the vehicle on days when you just want to get into a warm car. That is irrelevant to which is better for the car - sometimes you just don't feel like being cold!

themanwithsauce - has as many vehicles as job titles > Stang70Fastback 01/08/2014 at 11:21

2

I take 5-10 minutes of idling to warm up my jetta because I only drive 2 miles or so to work and repeated short trips causes condensation to accumulate in the engine oil. Idling it up to the 200F operating temp has helped out a lot since if I travel at speed and turn my heat to max, I can actually drop to 150 or so when it gets this cold out.

It's a 1998 with over 200k on it so I wouldn't idle it that long on a new car. It works for me and the car sips gas anyways so I figure it's better to just do it when it's near zero outside. I also row through my gears a few times to loosen up the shifter a bit and make sure my clutch isn't acting up.

Takuro Spirit > Stang70Fastback 01/08/2014 at 11:22

0

My routine goes like this.

Go outside . Is it cold?

If yes start car and sit inside. Is it too cold to drive? If yes leave car run, go back inside.

If no start car and leave after plugging in phone/turning on dashcam.

FlipperB > Stang70Fastback 01/08/2014 at 11:23

1

I'm firmly in camp #2.

It's essentially a choice of letting the engine run "cold" for 10 minutes in the driveway, where it's slow to warm up, or getting it warm in 3-5 minutes of gentle driving.

That said... the past two mornings were in the single-digits; both my engine and power steering were lugging and making [slight] audible complaints as I drove.

FJ80WaitinForaLSV8 > Stang70Fastback 01/08/2014 at 11:23

3

The reason I let my car warm up in the drive way is because I want the heater to work when I get in. Simple as that. I imagine most non-enthusiast favor this method as well for the same reason.

I do find however that a surprising number of people don't understand how heaters work. While car pooling and not letting the car warm up first they immediately turn the heater on. I turn it off, they get annoyed and say WTF. I explain the engine needs to be warm first - they still seem skeptical.

doodon2whls > Stang70Fastback 01/08/2014 at 11:27

1

#2

Modern lubricants and vehicle system designs (powertrain, drivetrain, chassis) are designed to work in sub-freezing temps. So long as you use the recommended fluids for your car, you should be fine with a brief (15-30 Second) warmup followed by moderate driving. Once the oil pump is primed and the critical engine components are lubed, moderate driving heats up the engine/oil more adequately.

In my turbocharged car, the ECU actually limits boost until the coolant temp is above 180*F, protecting itself from uncaring drivers. It also has an oil/water heat exchanger which acts to control the oil temp. It warms the oil during start-up and cools the oil once the engine has reached operating temps.

You should know that many auto manufacturers include 'cold start' as part of their Vehicle Functional Objectives. At one company I am very familiar with, that means the car is cold-soaked to -20*F and started with no jump box. There were pass/fail criteria for number of crank attempts, oil leaks, time to defrost the windshield and backlight, and time to target heater panel temps.

Eric the RC guy > Stang70Fastback 01/08/2014 at 11:30

3

My method this morning: start the car and let it run for 25 minutes because every window was frosted and the wind chill was about -15 F and I wasn't about to stand outside scraping my windows.

Normally what I do is let it run until it starts idling below 1500 RPM before I start driving.

Regardless of your method always drive slowly with low RPMs right after you take off in the cold. The engine oil might warm up, and the other fluids in the engine bay might warm up, but the transmission, tires, drivetrain, brake lines, power steering system, suspension, etc is still at ambient air temperature until the car is actually moving.

TheCraigy > Stang70Fastback 01/08/2014 at 11:30

2

For the newer stuff, most owners manuals state to let the car warm up during normal driving.

Just don't push it....

dinobot666 > Stang70Fastback 01/08/2014 at 11:30

1

When it's like -30F or lower, I let my truck warm up for a few minutes before I start driving. That's about it really.

McMike > Stang70Fastback 01/08/2014 at 11:31

12

#2 for me.

Letting your car idle in the driveway for 30 minutes doesn't hurt anything, it just wastes fuel, time, takes longer for it to heat up, and it makes you look like a pussy.

People sometimes make the mistake thinking that their transmission, differential, and other parts of the machine are "warmed up and ready to go!" once a little engine heat comes through the vents. Not the case.

Please keep throttle openings low, and revs down for the first 2-3 miles anyways.

I'm kidding with the "look like a pussy" comment.

No, I'm not.

Jayhawk Jake > Stang70Fastback 01/08/2014 at 11:31

1

Follow the manual. It's pretty clear what to do.

Turn the car on, wait for all the warning lights to shut off. Wait for the idle speed to return to normal.

I think what you should do on modern cars is just drive reasonably until the engine warms up. You won't blow up the engine doing this.

RacecaR > Stang70Fastback 01/08/2014 at 11:33

0

I am a #1-er. Mostly because I want my car to be warm when I get back in it. I hate being cold. So I start the car, turn the fan on high, and head back inside for a bit. After awhile (depending on how cold it is out) I go back out to my warm(ish) car and drive off.

And actually I was discussing this with someone else the other day. He said he had always got in his car and drove at a slow pace (not getting on it basically) until the car warmed up fully. So he is thinking more along the lines of #2.

Tom McParland > McMike 01/08/2014 at 11:33

0

What about letting it run for 5-10 minutes to defrost the ice off the windows?

Team6.1 > Stang70Fastback 01/08/2014 at 11:35

3

!!! UNKNOWN CONTENT TYPE !!!

Otherwise I am in camp #2. The only time I sit amd wait is if the windows are frozen over. If so start, scrape, go.

WhiskeyGolf > Stang70Fastback 01/08/2014 at 11:42

2

#2 for me

Mostly I sit and wait until the RPM drops to a more standard idle, as your manual suggests. Generally that's only 1-2 minutes depending on temperature.

McMike > Tom McParland 01/08/2014 at 11:47

2

As long as people understand that that it's an operator requirement, not a vehicle requirement.

There's a difference between, "It's bad for the car to drive it cold," and "I don't feel like scraping windows."

I've been talking about this over on Gizmodo this morning. No real harm letting it sit out there for 30 minutes so it's toasty warm, as long as they take it easy for a few miles, and don't claim that the engine needs it.

Even in the worst on conditions, the engine doesn't need more than a few minutes of idling before you can roll out.

overdrv > Stang70Fastback 01/08/2014 at 11:52

5

It's a Lease. Start and Drive

Thats why I think Canadians would make better tank drivers !!

willkinton247 > FJ80WaitinForaLSV8 01/08/2014 at 11:57

2

My car actually has an electric heater that is engaged when you put it on the full heat setting, so I'll put it on full heat, and run the fan at "1." The car begins to blow heat much faster, well before the engine fully heats up.

JEM > Stang70Fastback 01/08/2014 at 12:03

4

I definitely do #2.

Also, I make sure the transmission (manual), clutch, and brakes seem to be working ok when it's below 20F. Just a few times on each pedal, going through a couple gears, seems to help.

Fuel_of_Satan > Stang70Fastback 01/08/2014 at 12:13

1

1. Plug in engine pre-heater plug when you park.

2. Start your car and drive with a car pre-heated to 100F regardless of outside temperature.

3. Profit.

4. Huge loss as the electric bill comes in the mail.

tromoly > Stang70Fastback 01/08/2014 at 12:16

2

#2, because after a few seconds the oil pressure will come up due to the oil temp increasing due to viscous shearing. Basically, if you have good oil pressure, it doesn't matter if you let the engine sit there, the oil won't really change. Only thing sitting there would do is heat soak the block and coolant, which isn't necessarily a bad thing, it'll just open your thermostat when the coolant gets hot.

RotaryLover > Stang70Fastback 01/08/2014 at 12:17

1

One stupid thing I gotta say about my Mazda 3 2010, is the lack of a temp gage. When my heater is hot and that the idle goes under 900 after driving, I say myself that it's save to accelerate in the car...reading this I'm not so sure anymore.

Just4GP > Stang70Fastback 01/08/2014 at 12:19

1

#2 for me. My car will idle above 1500 until it's ready to go. I'm usually still easy on it til it reaches normal temps. This is before and after work.

On my last car, I had a remote starter which I used to start the car every time. Sometimes it would run a good 5 minutes before I got out to it.

FJ80WaitinForaLSV8 > willkinton247 01/08/2014 at 12:26

0

Interesting. What kind of car do you have?

willkinton247 > FJ80WaitinForaLSV8 01/08/2014 at 12:33

0

2010 VW Jetta LE

willkinton247 > FJ80WaitinForaLSV8 01/08/2014 at 12:33

1

Its an utterly brilliant feature.

CalzoneGolem > McMike 01/08/2014 at 12:34

0

I warm up my car for my children. Oh, I don't have to bring them today. Ooops.

McMike > CalzoneGolem 01/08/2014 at 12:45

1

I left that one out on purpose, since it didn't allow me to use the "look like a pussy" joke.

But that's a pretty good reason to let it warm up a little longer.

themanwithsauce - has as many vehicles as job titles > JEM 01/08/2014 at 12:45

1

Yep. I live up a steep driveway and off of a fairly busy street. I am going to have a bad day if my clutch, brakes, or gears are acting up.

JEM > themanwithsauce - has as many vehicles as job titles 01/08/2014 at 12:53

0

Hahaha, I exactly feel this. My house is one house away from a downhill stop sign and the road in front of my house is always shaded, hence always icy.

CalzoneGolem > McMike 01/08/2014 at 13:09

1

"Look like a good father" just doesn't have that ring to it eh?

Casper > Stang70Fastback 01/08/2014 at 13:12

1

I let my tight tolerance aluminum block engines warm up a little extra before I take off, but still only a couple of minutes at the most. If it's a turbo car it gets extra time to get the oil moving. If it's my bike, I let it warm up for a minute or two when first setting out in the morning or after work at night, but everywhere else it only gets 30 seconds to a minute as it should already have warm oil and oil moved around in the engine.

More than anything it depends on the oil I'm running and what the engine design is. I don't have a general blanket rule for all my vehicles.

MountainCommand > Stang70Fastback 01/08/2014 at 13:14

0

In temps below 20F, my car on its own idle power will not reach operating temperature. Ive sat in the car idling for well beyond an hour many times letting it run and my needle barely comes up to the first line.

So driving it is the only way to even get it to operating temperature. The gearbox on the other hand, always double clutching for the first few miles until warm.

JACU - I've got bonifides. > Stang70Fastback 01/08/2014 at 13:30

1

"We recommend that you drive moderately until the pointer of the temperature gauge reaches near the middle of the range, then floor it."

Perhaps that's not what it says, but...

Stang70Fastback > willkinton247 01/08/2014 at 13:35

2

Well that's pretty cool.

Stang70Fastback > JEM 01/08/2014 at 13:37

0

I learned that in a scary manner yesterday. Got to the end of my street and discovered my brake pedal would barely move. Had to stand on the pedal to not end up through the intersection. Turns out something was a bit sticky in the cold weather and I had to pump the pedal about ten times before it all started working normally.

Stang70Fastback > doodon2whls 01/08/2014 at 13:39

0

Interesting info. I know I have seen cars with active red-lines, where a row of red lights around the perimeter of the tachometer starts off coming all the way around to 3k or so, and gradually moves up as the engine warms up.

And obviously a lot of modern cars don't have the lights, but still limit RPMs in the same manner.

Stang70Fastback > themanwithsauce - has as many vehicles as job titles 01/08/2014 at 13:40

0

That does make sense for very short trips. I suppose how you drive your vehicle might affect how you warm it up.

Stang70Fastback > RacecaR 01/08/2014 at 13:41

0

And in your case, it sounds like you aren't a #1er just because you necessarily think it's better for the car, but mostly just because you want to be warm.

Stang70Fastback > MountainCommand 01/08/2014 at 13:43

0

What type of vehicle do you own? My Subaru doesn't have that small of an engine (2.5L) but it's still an aluminum block and cools very quickly, and yet even my car will warm up after 20 minutes of idling on VERY cold days (at least somewhat).

Stang70Fastback > RotaryLover 01/08/2014 at 13:45

1

Yeah, my mom's new(ish) Impreza just has a stupid blue idiot light that stays on until the engine is "warmed up" whatever that means. Never knew if that meant when the light went off it was completely warmed up and you could rag on it, or whether the blue light just means "I am VERY cold, please don't do anything stupid."

Echo51 > Stang70Fastback 01/08/2014 at 13:46

2

I just drop in, fire mine up, wait for the worst of the valve tapping to go away, and off i go, making sure to not hoon it untill it's warm. If you have oil pressure it doesn't really matter as far as i know. Only exception would be getting stuck the first mile before i get to plowed road or having to scrape abnormal amounts of snow off it...

^not the worst, but i once woke up to it having been full kamm-back'd. I smiled like a dork while scraping all the snow off.

See also: I hate spoilers for REASONS

Stang70Fastback > Fuel_of_Satan 01/08/2014 at 13:46

2

If I do end up ordering a BRZ sometime in the future, I will get the block heater - partly because I'll likely be moving to New York State for my job, but mostly because I like having all the options, lol.

RotaryLover > Stang70Fastback 01/08/2014 at 13:48

0

I don't even have the stupid blue light! You're left alone guessing...

Stang70Fastback > Echo51 01/08/2014 at 13:48

0

Heh, yeah, I usually give my car about 30 seconds to let some of the piston slap go away (though on cold days that takes a mile or more of driving).

Stang70Fastback > RotaryLover 01/08/2014 at 13:50

1

Oh. Well that is completely retarded (no offense.) I can see why that would drive you up the wall. That almost sounds like a liability in that no temperature gauge (or light) is less of a deterrent to people to not hoon their car before it is warmed up, which would theoretically mean more mechanical failures under warranty, and theoretically cost Mazda money.

Or they figure it will just cause premature failure OUTSIDE of the warranty, and make them MORE money...?

/jumping-to-tin-foil-hat-conclusions

MountainCommand > Stang70Fastback 01/08/2014 at 13:51

1

Last gen prelude. The 2.2L h22 series engine has FRM cylinder walls. And if memory serves me right, i read that with that material as well as other things, the engine ran rather cool. Which obviously wouldn't help in the winter.

RotaryLover > Stang70Fastback 01/08/2014 at 14:03

1

This is my thought also...a little bit. They keep saying, drive the car like you feel like driving when you start it...I play it safe.

Stang70Fastback > MountainCommand 01/08/2014 at 14:09

0

Ah, I gotcha. Well I suppose that sucks for days when you just want to warm the car up because you don't feel like being cold, lol.

Echo51 > Stang70Fastback 01/08/2014 at 14:41

1

Bought it with front end damage, found out the engine ran very unclean when we got it fixed to be driveable. Ended up swapping the entire head and got it past inspection with that, but it loves to rattle at low-load, 3k RPM+ driving. Surely it'll run anyway, if not i think we a head to swap from a 130hk engine... 25 horses extra, mhhhm :)

MountainCommand > Stang70Fastback 01/08/2014 at 14:45

1

Well, its not entirely terrible, i will still get nice warm heat. But it just means i cant be popin' vtec until im up to operating temps haha.

njohnson > Stang70Fastback 01/08/2014 at 19:23

1

Im on the side of #1

I live in a place where it is routinely at or below freezing at night and in the morning. lack of proper lubrication (meaning the oil in this case being the right viscosity to do it's job) is going to cause excessive heat and wear on metel componets it probably wont destroy your motor alone but consistantly doing this is certainly not good for it. im not saying idle your car for half and hr but imo its worth letting it idle 5-10 mins before driving because you allow the oil to heat up some and do its job. an example to show how viscous your oil is in your engine set a quart of oil out side (when its cold obviously) and one in your home wait till morning and go look at the oil it will be thicker and therefore not able to perform as well as the oil you will see inside.

juggaho > Stang70Fastback 01/17/2014 at 17:10

2

Anyone drive a car with a carb? Yeah, it's gotta warm up.

JasonSpeed > Stang70Fastback 01/17/2014 at 17:14

1

I'm late but I'll comment on the engine warm-up part. When the temperatures get into the low teens and below my engine makes different noises when it is first started. When it is this cold I let it idle until the engine sounds normal before I drive. When I start to drive I won't let the engine go above 4k RPM until I have gone a few miles, accelerating slowly. 2003 WRX.

RelentlessSlacker > Stang70Fastback 01/17/2014 at 17:16

1

On cold start my car idles at about 1250 RPM before dipping down to ~800 or so after a brief warmup period (as little as 0 seconds on a stupid hot day, maybe a full minute if it's below freezing) and then drive it gently (no WOT, stay in the first half of the rev range) until the coolant gauge reaches its full-warm, middle position.

Earthbound And Down > Stang70Fastback 01/17/2014 at 17:21

1

#2.

If you let your vehicle idle for too long to warm up without actually driving it, the piston rings do not fully seal against the cylinder wall/liner due to the lack of load placed on the engine as the crank goes through its motions, and small amounts of fuel will leak past the rings and into the oil. Enough fuel mixes with your oil over time, and its ability to lubricate will diminish over time, above and beyond what it normally would through normal operation under load.

That's why I've always let it warm up for no more than 30 seconds before driving lightly, without going through more than 30% of the rev range, I'd say (I shift between 2-3k with a redline of 8200).

(Also, fun fact: Your oil takes longer to warm up than your coolant does. If you only have a coolant temp gauge, don't assume that warm coolant means warm oil and mash the gas as soon as the coolant temp hits the normal operating range.)

At least that's what I was taught.

ApriliaFutura > Stang70Fastback 01/17/2014 at 17:21

1

#2 for me. 2010 Dodge Charger - fuel management means it sips fuel just idling and it took about 20min sitting in the driveway for the needle to come off the peg. 2-3min of idling after cold start and then driving off gently seems to bring all the fluids up to temp much quicker - within a half mile or so usually.

twochevrons > FJ80WaitinForaLSV8 01/17/2014 at 17:25

0

Heh, the climate control on my old Citroën Xantia didn't allow that to happen – in automatic mode, it would leave the fan off, or on low, until the coolant heated up. You could still manually turn the fan on by selecting a speed, but it made for great set-and-forget comfort. I'd hardly have to touch the controls year round.

ttopolds > twochevrons 01/17/2014 at 17:27

0

The automatic climate control in my old 97 Cutlass Supreme did the same thing. I miss having that.

AeroEagle333 > Stang70Fastback 01/17/2014 at 17:29

1

I'm on the side of #2. I usually give me car 30-60 seconds and taken off, giving the car plenty of time to warm up naturally before being aggressive with the throttle.

Also, FWIW, Connecticut state law doesn't allow idling for longer than two minutes (I may be wrong on the exact number, but it's low), so being a #1 wouldn't work out for me.

David Gabel > Stang70Fastback 01/17/2014 at 17:36

1

Reminds me of something I saw a few weeks back when we had single digit and often below zero temps. I was about to head home from the office, and some pinhead in the parking lot adjacent to my office got in his SUV, started it and revved it hard several times immediately upon turning the key in weather of about 3 degrees with a windchill of -2, and then proceeds to gun it when he leaves. Now, it's also not some old junker either. It was a 2013 GMC Denali Yukon. Guess he won't own that for long if he keeps it up.

UKPDXWRX > Stang70Fastback 01/17/2014 at 17:43

1

Turbo car here:

You can and I do drive immediately after starting the car in any temperature - but gently. If it's winter that's <= 3500 rpm and grandma throttle.

Once the needle starts to move at least I'll use a little bit more throttle.

Once the needle gets at least a 1/4 way up I'll accelerate moderately up to mid range RPM, but trying to stay out of boost.

Once it's in the middle range, it's party time.

UKPDXWRX > Casper 01/17/2014 at 17:45

1

Unlike my car I definitely like my bike to be a little warm, at least the time it takes me to put my helmet/gloves on and get settled, a little longer if it's starting from ambient.

I've got a 600 and the high idle is annoying and the throttle response is very muddy until the engine at least gets a couple minutes of heat into it. If you try and blip it right within 30 seconds or so of a cold start it'll just stumble instead (bike is well maintained and runs like a banshee when hot, it's just 2nd gen FI)

DipodomysDeserti > MountainCommand 01/17/2014 at 17:52

0

I'm guessing there is something wrong with your temperature gauge. In reality, ambient air temperature, unless extreme, should not affect car warm up too much.

Korea Miéville > Stang70Fastback 01/17/2014 at 18:30

1

My problem is that I live pretty close to the freeway I take to work, so I don't have much road available for gentle driving. I guess I could leave home early and just drive around the block a few times, but I'd feel kind of stupid doing it.

Skrammoof > twochevrons 01/17/2014 at 18:50

0

Ditto with the Auto setting of my old 2002 Audi A4.

Stang70Fastback > Korea Miéville 01/17/2014 at 19:07

0

I'm actually in your situation. From the time I pull out of my parking spot, I can be on the entrance ramp to the highway in 60 seconds. However, unless it's a particularly cold day outside, by the time I get up to speed on the highway, the temp gauge is already rising. Someone else pointed out that doesn't necessarily mean the engine OIL is up to temperature yet, but I suppose at least it's flowing, lol.

Stang70Fastback > David Gabel 01/17/2014 at 19:09

1

Poor Yukon :(

Stang70Fastback > ApriliaFutura 01/17/2014 at 19:11

0

That's a pretty big engine, relatively speaking... so I would imagine that thing takes a lot of heat to get up to temperature anyway.

Stang70Fastback > Earthbound And Down 01/17/2014 at 19:11

1

Interesting. Where did you learn the piston ring thing? Just curious - not that I don't believe you.

Stang70Fastback > JasonSpeed 01/17/2014 at 19:12

1

Do you get that piston slap noise that is all-to-familiar to me?

Stang70Fastback > juggaho 01/17/2014 at 19:12

0

Indeed, older cars are an entirely different ball game, lol.

JasonSpeed > Stang70Fastback 01/17/2014 at 19:38

0

Yep, sounds like the engine is knocking bad until it gets warm.

Ricky Weston > Stang70Fastback 01/17/2014 at 20:18

1

I usually let my car warm up for 2-4 minutes, then set off at a grandma's pace until the engine temp comes up. After 5-10 mins of driving, after the thermostat has opened, I figure the oil is warm enough to warrant more aggressive throttle use.

For my cars that have oil temp gages, I will apply the same procedure, but I will not really get on the gas until the oil is up to operating temp.

That applies to both winter and summer for me.

imadudeadam123 > Stang70Fastback 01/17/2014 at 20:36

1

My 2014 Mazda3 has this feature:

ACCELERATEd WARM-UP SYSTEM (AWS)

Vehicle Starting:

Your vehicle is equipped with SKYACTIV combustion technology. This

technology includes AWS (Accelerated Warm-up System) for optimal

emission performance during cold starting conditions.

Cold Start (e.g., First start of the day on cold mornings):

Depress the brake (Automatic Trans.) or clutch (Manual Trans.), when the key

indicator light turns green (if equipped) push the START/STOP button.

What you will notice: On start-up, the engine speed and sound are

higher (1500 RPM) for 30 seconds to 1 minute to quickly bring the catalyst

to efficient operating temperature. The RPM will reduce to idle once the

temperature is achieved. This is normal engine operation under cold

start conditions.

eM > Stang70Fastback 01/17/2014 at 20:58

3

e39 M5 will suggest (though not govern) you keep your revs reasonable.

Stang70Fastback > JasonSpeed 01/17/2014 at 21:03

0

Yay for worn piston rings!

Stang70Fastback > eM 01/17/2014 at 21:05

2

I prefer that to the more modern vehicles that actually DO govern revs. Not that I would want to exceed what the vehicle recommends (it's not doing that to annoy you) but I picture a scenario one day where a Tsunami happens to make it all the way to... Blacksburg... Virginia... and I have all of 10 seconds to get to my car and out-run the wall of water. The last thing I want is my car limiting me to 3k RPM because it doesn't want any extra wear and tear!

JasonSpeed > Stang70Fastback 01/17/2014 at 21:07

1

The car sounds like it is sneezing when I first start it below zero now. The sooner the engine dies the sooner I have an excuse to drop in a 257 short block.

94GTratracer > Stang70Fastback 01/17/2014 at 22:08

1

OBD1-era vehicle owners: I have a wideband AFR gauge installed and I've noticed that air-fuel ratios don't pick up the signal from the O2 sensor immediately. I wait until I can run in closed loop, but that's less than 5 min.

The WB > juggaho 01/17/2014 at 22:48

0

I had a carb on the '67 Mustang. It actually ran in the cold without any problems or idling required. But then again, that's Texas cold, which is rarely under 20F.

The WB > Stang70Fastback 01/17/2014 at 22:54

2

Why do people think that increasing oil viscosity is bad for bearings?

It actually increases hydrodynamic film thickness, making it harder for the metal to touch.

There isn't going to be a whole lot of localized heating because of that. You're just more likely to blow your oil galley plugs out of the block.

What causes problems is increased clearances due to differing coefficients of thermal expansion - as well as thermal shock from very high temp differentials. Piston slap especially.

I am a strong proponent of #2. Let it idle enough to get fluids gently stirring, then don't rag on it until its been up to temp for a while.

nycsingletrack > MountainCommand 01/17/2014 at 22:59

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It sounds like you have a thermostat that is stuck open, or won't close completely.

EvilFD > Stang70Fastback 01/17/2014 at 23:06

1

Seems like alot of people are struggling with reading comprehension. That and differentiating between driver confront, and the point of the conversation, whats good and or necessary for the car.

I'm pretty simple. In both of my performance vehicles I'll sit in them or let them sit long enough to completely warm up. Even then I'll take it easy on the car for the first five or ten minutes at least.

With my daily driver I'll let it warm up a couple of minutes then just drive in the least aggressive possible way until it reaches normal operating temps.

With your day to day car, I really don't think it makes all that much of a difference. Even with my two performance cars its probably not that big of a deal so long as I pussy-foot around until they're up to temp. But, on built motors, built transmissions, turbos, and especially E85 (i.e big investments and tighter, more exacting tolerances) I'd just assume to play it safe and let them warm completely up before I even back out of the garage.

Raymax > doodon2whls 01/17/2014 at 23:13

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Just to play devils advocate on the water/oil heat exchanger, I have read that it may actually make your oil take longer to heat up due to the release of cold coolant into the system once the thermostat opens up. No first hand experience, so grain of salt and all that...

SirRaoulDuke > RotaryLover 01/17/2014 at 23:16

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If it bugs you that bad I'll trade you my 04 3, complete with awesome temperature gauge.

doodon2whls > Raymax 01/17/2014 at 23:17

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The release of cold coolant is short lived as the thermostat will (should) regulate the engine circuit coolant to the desired temp. A proper oil cooler configuration is in the engine coolant circuit so it will warm the oil more quickly. OK, that sounds counter intuitive b/c we unfortunately call it an oil cooler. It's actually an oil/coolant heat exchanger. There. That's better.

gmporschenut also a fan of hondas > Stang70Fastback 01/18/2014 at 01:21

1

I always wait until my window defrosts. I don't mean the outside stuff I'm talking the interior fog that forms 3 mins after starting, but before the car is warm. I drive east in the morning, into the sun, and one morning just after leaving my window does that fog thing + the glare. I start to gently brake, put my window down and slowly move my car into the first availible turn. So always make sure your windshield isn't going to fog. Then drive. Or live east of your destination.

Drifton Aloft > Stang70Fastback 01/18/2014 at 01:47

1

So while its not a car, My '07 250 ninja it Kawasaki recommends 10-15 minutes of actually driving for everything to warm up

Dr.Kamiya > Stang70Fastback 01/18/2014 at 02:00

1

I put some kindling under the car and...

Intending_Acceleration > McMike 01/18/2014 at 02:49

1

Letting your car idle in the driveway for 30 minutes most certainly does hurt things. Your engine's clearances are set for operating temperature, and at idle, in the winter, it takes a long time for the engine to get up to operating temperature. You're causing significant wear and tear on the bore and rings, for example. 700 revolutions per minute for 30 minutes = 21k revolutions at sub-operating-temp.

A few minutes driving will bring everything up to temperature. 2,000RPM for 5 minutes? 10k revolutions.

In short: start the car and idle it long enough to figure out things are working properly, get the seatbelt on, fire up your GPS, fiddle with the radio...then drive. In a turbocharged car, stay out of the boost until you see OIL temperature past 60C.

Intending_Acceleration > Skrammoof 01/18/2014 at 02:52

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It's a feature on Audis that dates back to the 80s when they used GM climate control units. The blower fan doesn't come on until a set temperature unless you switch modes.

Intending_Acceleration > Stang70Fastback 01/18/2014 at 02:54

0

That's not piston slap; it's the lifters, most likely.

DangerRanger > Stang70Fastback 01/18/2014 at 02:59

1

My answer is really none of the above. It is:

Exactly as long as it takes for the defroster to work well.

Whatever the wear on the engine, it's even more important to be able to drive properly. When it gets truly cold, your breath will condense and quickly freeze on the windows. That makes frost. You can't see through frost, and I'm pretty sure we all know that we should be able to see if we're driving.

Whatever engine warmup procedure is best for the engine, the best one for the car as a whole (and the driver for that matter) is the one that makes it less likely to smash into something that you couldn't see, or didn't notice because you were scraping the inside of the windshield with your cell phone.

And it doesn't even take toasty warm to defrost. As soon as the air out of the vents is above freezing, it will clear the inside of your windshield, but still feel pretty cold. It takes different amounts of time for different cars/engines to reach that temperature, but in a lot of cases it's less time than you'd expect.

Your engine will survive a lot of warmups that that might or might not be wrong better than it will survive you breaking its radiator on a tree after missing a corner you couldn't see.

Easy E > MountainCommand 01/18/2014 at 04:02

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Heh, I once owned a '84 diesel VW rabbit. In very cold temps (below -10°C) I'd often leave the bloody thing running while in class or shopping. I could leave it for hours with the temp guage barely past rest position. nm it used next to no gas at idle...

Echo51 > UKPDXWRX 01/18/2014 at 06:19

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Stay out of boost? You running a ferry turbo on a honda vtec? Most cars should boost around 2k rpm or so, otherwise the turbo would just be a nuisance for everyday driving :)

Echo51 > imadudeadam123 01/18/2014 at 06:23

1

Which is for decreasing emissions/lighting off the cat, the extra heating is just a side effect because it has to produce the extra heat for the cat :)

webmonkees > Stang70Fastback 01/18/2014 at 07:07

0

VW with electronic fuel injection etc: enough for the idle to stabilize. Better when warm, and there's that whole temperature in the cabin thing that warm-up helps.

Subaru with carburetor: 3 minutes minimum. There is an 'optimal operating temperature', and cringe when I see somebody just jump in their Outback and just go. A couple minutes, come on. Be nice.

Typically, though, I judge readiness by how easy it is to clear the frost. I've skipped that step sometimes.

Stang70Fastback > Intending_Acceleration 01/18/2014 at 07:48

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Nope, it's piston slap. It's a common issue on older Subarus, at least. It goes away after a few minutes once they warm up and expand a bit.

Stang70Fastback > gmporschenut also a fan of hondas 01/18/2014 at 07:50

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I've actually never had that issue before, I think. Except that thick, watery fog as a result of high humidity, but never as a result of the sun.

Stang70Fastback > webmonkees 01/18/2014 at 07:52

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You aren't suggesting that Subaru Outbacks have carburetors... are you? Lol.