Is it necessary to warm up my car?

[Peppy]

I've heard so many conflicing opinions.

I have a 2000 Acura Integra GSR.

I heard that there is no need to warm up a Japanese car buton the other hand, it's crucial to warm up a domestic.

what's the deal?

[Coldfire]

If by "warming up" you mean "going easy on the first couple of minutes of driving": that goes for ALL cars.
And it's not so much about temperature. It's about oil. When your car sits in the driveway (not running), the oil in the engine and transmission logically flows to the lowest point (don't ask me to name these parts, I'm not a mechanic). When you start her up in the morning, the oil takes a while to reach all parts of the engine. So, when it's "cold", you're basically driving without oil. If you really floor it then, you're possibly damaging the valves et cetera. If you wait (about 5 minutes of driving will do the trick), the oil is evenly spread, and the car can handle high revs much better.

[Northern Piper]

Peppy, I agree with Coldfire, but would like to ask a follow-up question: how cold is it outside when you're starting your car? If it's really cold, then the other fluids (the steering fluid and the brake fluid) can also be pretty viscous, and that means your power steering and power brakes may not work very well until they get warmed up.

For example, the other day here it was -32° Celsius. I didn't let it run long enough, and the first intersection I came to, the brakes were pretty sluggish - I slid into the intersection a bit. So, if it's really cold, let it run for oh, five minutes, and be sure to pump the brakes a few times before you start out.

(I know that Click & Clack, as well as car manuals, say that you shouldn't run the car as a warm-up, but that's assuming reasonably warm temperatures, like in the -5 to +10 range.)

If you get a block heater and plug the car in overnight, there's much less need to run the car in the morning - the oil will still have settled, but it won't be as viscous, and won't need as much time to get evenly distributed.

You can also get oil for cold temperatures. The usual rating is 10W30, where the "10" is the viscosity of the oil before it starts up. For really cold weather, you can get 5W30, or even 0W30 - but check your owner's manual to see if those oils can be used in your engine. If you do use one of those cold weather oils, there's less need for the warm-up.

[handy]

Peppy, why don't you look at the owners manual??? Cars come with those things & let us know what it says.

Also, when you read it, would you check on the oil change
interval? Some guy told mee this week that a Honda 2001 can go without oil changes or adding oil for 10,000 miles but I don't think this is possible.

[Diceman]

Handy: Sure, a Honda 2001 could go 10,000 miles without an oil change, but you'll be in need of a new engine a heckuva lot sooner than you were planning ;)

[barbitu8]

I have a 94 Civic and the manual says to change the oil every 7,000 miles. But that's under ideal driving conditions. Fortunately, I don't live in the harsh winter climes any more, but I still do a lot of city driving. i change my oil every 3,000 miles whether it needs it or not, and that includes the oil filter. Oil and filters are cheap compared to a new engine.

[Tedster]

Freezing temperatures are hell on automobiles.

With that out of the way....

It isn't necessary nor desirable to "warm up" an engine, either foreign or domestic, for an excessive amount of time, say 20 minutes. The reason for this is simple. Careful studies have shown that getting the engine to normal operating temperature as fast as possible is best for engine wear, oil dilution, emissions, mileage, etc.

So, a sort of modified warm up procedure is to let the car idle for 2 to 5 minutes in subzeroish weather to allow oil to circulate, and then put the engine under a light load, that is, driving till the temperature indicator is in the normal range. That means no highway speeds for about 15 to 20 minutes. Makes sense to me.

[barton]

This may be somewhat unrelated, but in response to the earlier mention of brakes being sluggish at first - the tires might be part of that problem, too.

They warm up after awhile, and when they do, your grip on the road increases. Witness the Indy drivers weaving back and forth on the caution laps to keep their tires toasty.

[hockeynut]

I worked for Chevrolet Motor Division a few years ago and we got this question a lot from our customers. Our tech group had this opinion:

Your engine will experience more wear and tear when the engine is cold. Cold oil doesn't circulate as well as warm oil, so your cylinders and rings don't get as much protection. However, idling your car for a few minutes after starting it isn't the answer. You will get the same amount of wear and tear whether you are driving normally or idling.

You might see sligtly more damage if you run your engine at very high rpms when cold. However, if you are racing your car around all the time, you're probably causing all kinds of damage and a cold engine is the least of your worries.

One way you can protect your engine from cold starts is a block warmer (an electric warmer used to heat your engine block in cold weather).

Of course you will probably spend more on electricity than what it cost to rebuild or replace your engine. Block warmers are really only necessary where the average temperature is so cold that your car won't start, like the Arctic Circle.

You could also use an oil with a different viscosity (5w30 rather than 10w30) in cold weather, though that is not recommended on a lot of newer cars.

[flyboy]

hockeynut writes "However, if you are racing your car around all the time, you're probably causing all kinds of damage and a cold engine is the least of your worries."

I hate to get away from the OP, but I have to ask... my brother says that cars are built to endure high rpms and that you're not doing much damage at all by "racing" around at 4 or 5000rpm (assuming that's not red-line range). I may do this at a stoplight once in a while, just to get the old testosterone flowing, but like my suv too much to do it more often. Is he right, or should I keep it at lower (read: less manly) rpms?

[wevets]

I had some difficulty with my car earlier this year and had to take it in to a mechanic, who replaced the transmission-clutch solenoid. After he did it, he advised me to always warm up the car after I started it, which I did (not wanting any more trouble). Was he mistaken?

[Una Persson]

Originally posted by flyboy88
hockeynut writes "However, if you are racing your car around all the time, you're probably causing all kinds of damage and a cold engine is the least of your worries."

I hate to get away from the OP, but I have to ask... my brother says that cars are built to endure high rpms and that you're not doing much damage at all by "racing" around at 4 or 5000rpm (assuming that's not red-line range). I may do this at a stoplight once in a while, just to get the old testosterone flowing, but like my suv too much to do it more often. Is he right, or should I keep it at lower (read: less manly) rpms?

First off, I agree pretty much with what hockeynut says.

Second, yes, many cars are designed to run at higher engine speeds than others. Often this is out of necessity, as the power band of the engine may require a much higher rpm than other cars - especially true on small displacement and/or short stroke engines.

When someone says a car's engine is "built for higher rpms", it typically means, in a real-World situation, that the engine is much more able to withstand the cyclic stresses of the higher engine and piston speeds, and has a better design that reduces unwanted vibration - both the annoying type, and the destructive type.

That having been said - a higher engine speed means a higher peak piston speed, and thus (normally) a higher amount of piston ring wear. So while the engine may be well suited to running at higher rpms, this by no means says that you are not causing additional, extra, unneeded wear.

Short answer - lower rpms, within reason, typically mean less wear.

[DVous Means]

Just to back up what hockeynut said...

I own a Camira, built by General Motors' Australian Division, Holden. It's actually a local version of what was sold in Britain as the Vauxhall Cavalier. i believe the original idea was a J-car concept designed by Opel.

In my owner's manual, it states clearly that idling a car to warm it up is both unnecessary and a waste of fuel. The manual recommends that the car be started and driven as normal, even when it is stone cold.

[Coldfire]

I think idling a car makes little sense, but doesn't the manual warn for TOO much pressure on the car during the first minutes? "Driven as normal" is NOT the same as "Driven while cold" in my book.

I mean, that's an OZ Opel Vectra right there. If their European counterpart is any indication, these things need all the precautions you can supply them with. ;)

[Una Persson]

To add some more info here...

What do I actually do with my car, my Mustang? Well, I have it in a heated garage, so it never gets terribly cold. Still, I let it idle for about 3 minutes each morning, just for my own peace of mind and to let it warm a little bit. And I don't step on the gas hard at all until the temperature needle is past the bottom of the "Normal" band on the temperature gauge. I also change the oil every 3000 miles; for debate about this topic do a search - this has been covered ad nauseum.

Since my car has the 4.6 liter "Modular" engine, 5W30 is the recommended oil. But Ford will allow 0W30 for cold climes, and many Modular performance enthusiasts will run 0W30 in it anyhow, to get a little more power at high speeds (with a cost of more potential engine wear).

[handy]

My manual states to let it warm up for 10 seconds at least, which is reasonable. It let's the choke work right, see?

Plus, don't forget there is a specific starting sequence that youll only find in the manual for the car. For some reason people don't read the manuals. e.g. when cold, push the gas pedal all the way, start, wait 10 seconds push pedal half way. duh.

[OxyMoron]

Originally posted by DVous Means
Just to back up what hockeynut said...

I own a Camira, built by General Motors' Australian Division, Holden. It's actually a local version of what was sold in Britain as the Vauxhall Cavalier. i believe the original idea was a J-car concept designed by Opel.

In my owner's manual, it states clearly that idling a car to warm it up is both unnecessary and a waste of fuel. The manual recommends that the car be started and driven as normal, even when it is stone cold.


I don't doubt your cite in the slightest - but I'm suspecting that the advice may be different for Australia and Britain because (generally speaking) temperatures don't get anywhere near as cold in those two countries as they do in the middle of North America, where for months on end large swathes of territory never even get to the freezing point. I'm willing to bet that the Plains and Great Lakes regions of North America have the most extreme annual temperature shifts of any place on earth (in Farenheit, a normal year might range form -20 to +105), with the exception of a few thinly-populated areas of central Asia.

Oh, and Detroit's smack in the middle of it.

[Coldfire]

Originally posted by handy
For some reason people don't read the manuals. e.g. when cold, push the gas pedal all the way, start, wait 10 seconds push pedal half way. duh. No, not "duh". "Huh?" is the right answer.

Are you suggesting you should start a car with the gas pedal floored, or even slightly applied? It is my understanding that a modern fuel-injected car (which in 99% of the cases means it has an automatic choke) needs to be started without any use of the accelerator. Stepping on it causes the fuel lines to pen too wide, thus providing the engine with too much fuel for a start-up combustion. A modern cars motor management system handles temperature changes just fine. I've started my car (1996 Peugeot 306) in temperatures ranging from -25 Celcius to +45 Celcius, never applying the accelerator. IF it's cold, the engine just revs higher on the automatic choke.

Duh.

[barbitu8]

A modern car with fuel-injection must be started without using the accelerator, as you said Coldfire. Handy's advice is only applicable to those clunkers that still have carburetors, if there are any left.

[barbitu8]

Oh, BTW, cars with fuel injectors don't have automatic chokes. They don't have any choke. The computer decides the proper mixture of fuel and air.

[handy]

Coldfire, that's what one of my manuals said. It was just an example of what manuals say, since no one here seems to read theirs. Otherwise we wouldn't be answering this question. duh.

[Northern Piper]

And I don't step on the gas hard at all until the temperature needle is past the bottom of the "Normal" band on thetemperature gauge.

Again, the advice on this point depends on how cold it is outside when you start your car. Some mornings when I drive to work, the engine temperature gauge hasn't budged even by the time I'm parking the car at the office, a trip of a couple of miles. This is very much a YMMV situation.

[Tedster]

Those are considered the hardest miles on an engine, any gasoline engine at least-- those trips which don't allow the engine to reach normal operating temperature. Modern engines warm up much quicker than engines of yore, to be sure, and with a lot less emissions too.

Muffler replacement is another classic-- old guys who hardly ever put any miles on their cars are always putting new mufflers on because the engine never warms up..., leaving all that condensation and vapor to corrode the muffler.

Essentially you end up with a mixture of water, unburned fuel, and combustion byproducts in the oil sump as well. This is a Bad Thing(TM) forming sludge and acids. Driving "normally" before the engine is at the correct operating temperature is stupid.

[Northern Piper]

tedster, you say it's stupid, but what are my options? I have to drive "normally," to keep up to traffic - if I creep along at 5 or 10 km, I'll get ticketed for driving too slow/creating a hazard, etc.

[Una Persson]

Originally posted by jti
And I don't step on the gas hard at all until the temperature needle is past the bottom of the "Normal" band on thetemperature gauge.

Again, the advice on this point depends on how cold it is outside when you start your car. Some mornings when I drive to work, the engine temperature gauge hasn't budged even by the time I'm parking the car at the office, a trip of a couple of miles. This is very much a YMMV situation.

I offered my advice anecdotally, not with my Engineer's Hat on. Every time a subject like this, or oil changing, or proper oil weight etc comes up, I've found it's pointless to try and even recommend anything here. We have a mixture of half-remembered rules of thumb, 13-year olds posting from the standpoint of their "immense automotive experience", and pure madmen and madwomen who pop in with potentially destructive one-liners that their neighbor Biff (who's good with Commercial Loans, so he must know a lot about cars, as opposed to that crazy lesbo Engineer online) seem to make up on the fly.

Ultimately, handy had a good point about the owner's manuals; it just needed to be expressed a little clearer to have an effect.

Now I must go over and fight ignorance again in the latest Torque vs. Horsepower thread. ;)

[Homer]

We have a mixture of half-remembered rules of thumb, 13-year olds posting from the standpoint of their "immense automotive experience", and pure madmen and madwomen who pop in with potentially destructive one-liners that their neighbor Biff (who's good with Commercial Loans, so he must know a lot about cars, as opposed to that crazy lesbo Engineer online) seem to make up on the fly.

Well, I'm 19, but... ;)

Coldfire True, but most oil is formulated so that the particles are 'sticky' enough to 'cling' to the engine after it's cooled. IIRC an engine is really only 'dry' of oil if it's been sitting idle for a week or so. I don't know how often you change your coolant, but the fluid in the water jackets will be HOT for a LONG time after the engine is silent.

Also, the oil is picked up and circulated at the first tap of the ignition, so lack of oil isn't really a big concern.

handy The 5.7l V8 in the new Corvettes' oil change schedule was lengthened to 15000 miles in 2000 with use of Mobil 1 (stock full synthetic).

Diceman I can't say I'm an authority, but I have a 3.1 V6 that gets oil every 5000 (in a perfect world) or so miles, at 140,000, and it burns zero oil. Yeah, it's valves are mewling so it's within 20,000 miles of me needing to rebuild the head(s), but still, that's 160,000 miles with God knows how poor of service it received for the first 112,000.

barton is right in that a vehicle's brake pads, rotors, and tires all need to be warm before they work. If your brakes feel smushy after they are warm, check the pads and then change the brake fluid. If they're still smushy, make sure that the fluid is (was) bled right, and that the rubber lines from body > caliper aren't worn.

wevets could you explain to me what a transmission-clutch solenoid is? Does it go after the radial-arm plug or behind the air speed converter? I think you mean TCC solenoid.

DVous I looked up Caminas, and while they vaguely resemble the J-body we have in America (one of which I own), I'm not sure yet if they had the same platform, maybe just the same designation. More information, I can see, must be sought.

handy what the hell type car do you drive? You say "Owner's Manual" which means it came carburated stock. I don't know if you notice, but new cars don't have carburation. That information, then, is useless. The only cars these days with carburators are 1) old ones and 2) custom built ones.

Coldfire I may be wrong, but you can't flood a fuel injected vehicle. If you look at the actual linkage, your fuel pedal ONLY connects to the throttle body butterfly. Pushing the throttle opens the butterfly further, allowing more airflow into the intake runners. It is the increased air flow, measured by the MAP or MAF (mass air pressure or mass air flow) sensors that increases the amount of fuel fed into the engine, as determined by the computer.

Modifications to my car, for instance, has doubled the idle speed (500 rpm to 1000 rpm) because I removed the intake-air heater system which warms intake air thereby decreasing its volume. With the tube removed, the air is much colder and therefore tells the MAP sensor I'm getting much more air and the idle speed is thereby increased.

Tedster could you explain how a mixture of "water, unburned fuel, and combustion byproducts" in the oil pan? During combustion, these remain in the cylinder or are removed via the exhaust (which is what this mixture essentially is) and at no point migrate outside the cylinder. I was under the impression that the vast majority of damage to oil is done by heat, pressure, and friction, and not accumulatives.

BTW, Anth, I put a 160* thermostat in last night. :)

--Tim

[Moe]

Damn Homer, I'm automobilically illiterate, and going through hell right now with my car. We gotta talk. :)

[handy]

Carburators are cool! 1.One of the major advantages in using the carburetors is in it's throttle response 2. the carburetors need no intervention of ECU's which can be both expensive and in most cases limited in adjustability 3.the carburetors can be adjusted for much wider variety of engine setups using the same unit for the most part. Since
the carburetor's adjustment is in the jets alone, it can accommodate, high-comp, high-cam, uppper rpm or lower rpm, stroker,
etc...and almost anything you can imagine...as long as it's normally aspirated. 4.The setup simply looks really nice!!!! and it sounds mean!

[barbitu8]

Give me fuel injectors any day. No worry about the choke. It also seemed like carburetors don't last all that long, and parts, such as the butterfly valve, get defective. Hey, this is the Age of Computers. Get with it!

[Homer]

Originally posted by handy
1.One of the major advantages in using the carburetors is in it's throttle responseWhich is certainly no quicker than a fuel injected engine's. 2. the carburetors need no intervention of ECU's which can be both expensive When they go bad, which is almost never. and in most cases limited in adjustability A car's ECU is infinately adjustable at any RPM range of the engine. It can run separate routines depending on engine speed, temp, air temp, etc. A car's computer can have thousands of variables and scripts. You set a carburator once, and forget it. Which is more versatile? 3.the carburetors can be adjusted for much wider variety of engine setups using the same unit for the most part. Since
the carburetor's adjustment is in the jets alone, it can accommodate, high-comp, high-cam, uppper rpm or lower rpm, stroker,
etc...and almost anything you can imagine...as long as it's normally aspirated.See above. And it's only for n/a engines, huh? Well, I'm sold. What about a computer controlled engine that not only can be turbo or supercharged, but also can be adjusted, automatically, for higher/lower boost at certain engine/vehicle speeds, conditions, etc., I guess that's no good, huh? :rolleyes:

--Tim

[Badtz Maru]

Originally posted by handy

Peppy, why don't you look at the owners manual??? Cars come with those things & let us know what it says.

Also, when you read it, would you check on the oil change
interval? Some guy told mee this week that a Honda 2001 can go without oil changes or adding oil for 10,000 miles but I don't think this is possible.

I have a 2001 Honda Civic EX. We were told to get the first oil change at 7000 miles. I'm not sure what the interval is after that, but I know they switched 5W20 oil as the standard and that might last a while.

I have a '92 Honda Civic that has been driven several tens of thousands of miles without oil changes. It has 186,000 miles on it, and I doubt it's had the oil changed more than 7 or 8 times.