Car Care Myth
09-29-07, 10:41 PM
#1
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Car Care Myth
I know this is a beat down topic but this just made me mad.
http://finance.yahoo.com/insurance/a...s-and-Mistakes
They're sayin its harder on the engine, but apparantly does no wear on it than if its at idle, which contradicts their statement. I warm up my car summer or winter, i can tell the difference when the engine is running hard or not.
http://finance.yahoo.com/insurance/a...s-and-Mistakes
Myth: Wait, it's still warming up
Some people insist that your car will last longer if you let it idle until the engine reaches normal operating temperature.
It's true that running cold is harder on an engine than running warm. The oil is thicker, and it takes a little time - very little, really - for it to flow to all the parts of the engine that need it.
But letting the car sit while the engine is running doesn't help anything. It just wastes gas and pumps out needless fumes. You might as well get on your way.
Some people insist that your car will last longer if you let it idle until the engine reaches normal operating temperature.
It's true that running cold is harder on an engine than running warm. The oil is thicker, and it takes a little time - very little, really - for it to flow to all the parts of the engine that need it.
But letting the car sit while the engine is running doesn't help anything. It just wastes gas and pumps out needless fumes. You might as well get on your way.
09-29-07, 10:49 PM
#2
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I know this is a beat down topic but this just made me mad.
http://finance.yahoo.com/insurance/a...s-and-Mistakes
They're sayin its harder on the engine, but apparantly does no wear on it than if its at idle, which contradicts their statement. I warm up my car summer or winter, i can tell the difference when the engine is running hard or not.
http://finance.yahoo.com/insurance/a...s-and-Mistakes
They're sayin its harder on the engine, but apparantly does no wear on it than if its at idle, which contradicts their statement. I warm up my car summer or winter, i can tell the difference when the engine is running hard or not.
09-29-07, 11:10 PM
#4
Wrong.
They are neglecting the impact of metal expansion, whether it be the pistons, rod/crank bearings, or any other moving part. When considering the precision that parts are manufactured at, it can be a big deal. Running an engine hard when its cold can cause some serious issues. I've seen several engines die from oil starvation when they were ran hard when cold. Anyone who says its not a big deal just hasnt been around car engines long enough, I've had personal experience with that issue on my 240sx. I gunned it hard to high rpm when it was cold to get out into traffic and I now am getting a ticking rod bearing and the motor will go eventually.
You most likely can tell the difference when your car is warm or cold because it uses different fuel/ignition maps based upon the coolant temp/ambient temp, etc. The 2jz is a good example; one of its base functions is to adjust the amount of fuel injected based upon some logarithmic scale of the coolant temperature. And thats an engine that was designed 15 years ago, most of the functionality within those old 8bit and 16bit MCUs was a lookup table since the chips werent fast enough to actually make the calculations on the fly; the newer ECUs have not been cracked (although they are easy to flash nowadays), but the underlying operating system code still hasnt been cracked. The newer ECUs most likely run much much much faster hardware that can make many more cals on the fly.
They are neglecting the impact of metal expansion, whether it be the pistons, rod/crank bearings, or any other moving part. When considering the precision that parts are manufactured at, it can be a big deal. Running an engine hard when its cold can cause some serious issues. I've seen several engines die from oil starvation when they were ran hard when cold. Anyone who says its not a big deal just hasnt been around car engines long enough, I've had personal experience with that issue on my 240sx. I gunned it hard to high rpm when it was cold to get out into traffic and I now am getting a ticking rod bearing and the motor will go eventually.
You most likely can tell the difference when your car is warm or cold because it uses different fuel/ignition maps based upon the coolant temp/ambient temp, etc. The 2jz is a good example; one of its base functions is to adjust the amount of fuel injected based upon some logarithmic scale of the coolant temperature. And thats an engine that was designed 15 years ago, most of the functionality within those old 8bit and 16bit MCUs was a lookup table since the chips werent fast enough to actually make the calculations on the fly; the newer ECUs have not been cracked (although they are easy to flash nowadays), but the underlying operating system code still hasnt been cracked. The newer ECUs most likely run much much much faster hardware that can make many more cals on the fly.
Last edited by Bean; 09-29-07 at 11:14 PM.
09-30-07, 12:50 AM
#5
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Wrong.
They are neglecting the impact of metal expansion, whether it be the pistons, rod/crank bearings, or any other moving part. When considering the precision that parts are manufactured at, it can be a big deal. Running an engine hard when its cold can cause some serious issues. I've seen several engines die from oil starvation when they were ran hard when cold. Anyone who says its not a big deal just hasnt been around car engines long enough, I've had personal experience with that issue on my 240sx. I gunned it hard to high rpm when it was cold to get out into traffic and I now am getting a ticking rod bearing and the motor will go eventually.
You most likely can tell the difference when your car is warm or cold because it uses different fuel/ignition maps based upon the coolant temp/ambient temp, etc. The 2jz is a good example; one of its base functions is to adjust the amount of fuel injected based upon some logarithmic scale of the coolant temperature. And thats an engine that was designed 15 years ago, most of the functionality within those old 8bit and 16bit MCUs was a lookup table since the chips werent fast enough to actually make the calculations on the fly; the newer ECUs have not been cracked (although they are easy to flash nowadays), but the underlying operating system code still hasnt been cracked. The newer ECUs most likely run much much much faster hardware that can make many more cals on the fly.
They are neglecting the impact of metal expansion, whether it be the pistons, rod/crank bearings, or any other moving part. When considering the precision that parts are manufactured at, it can be a big deal. Running an engine hard when its cold can cause some serious issues. I've seen several engines die from oil starvation when they were ran hard when cold. Anyone who says its not a big deal just hasnt been around car engines long enough, I've had personal experience with that issue on my 240sx. I gunned it hard to high rpm when it was cold to get out into traffic and I now am getting a ticking rod bearing and the motor will go eventually.
You most likely can tell the difference when your car is warm or cold because it uses different fuel/ignition maps based upon the coolant temp/ambient temp, etc. The 2jz is a good example; one of its base functions is to adjust the amount of fuel injected based upon some logarithmic scale of the coolant temperature. And thats an engine that was designed 15 years ago, most of the functionality within those old 8bit and 16bit MCUs was a lookup table since the chips werent fast enough to actually make the calculations on the fly; the newer ECUs have not been cracked (although they are easy to flash nowadays), but the underlying operating system code still hasnt been cracked. The newer ECUs most likely run much much much faster hardware that can make many more cals on the fly.
Good post....
09-30-07, 01:39 AM
#6
HAHA I don't care really about warming up or not
... I just start up and go, or if i need to do something, it sits there and runs for a minute...Cause in the end...just doing this won't save you any more $$/time.
I mean, just how much wear does starting up/warming/driving cause?
Time for Myth Busters!
... I just start up and go, or if i need to do something, it sits there and runs for a minute...Cause in the end...just doing this won't save you any more $$/time.I mean, just how much wear does starting up/warming/driving cause?
Time for Myth Busters!
09-30-07, 02:53 AM
#7
Lexus Fanatic
'Running hard cold'... err i dont think thats the point here...
You start the car, wait 30sec for the oil to get flowing, off you go. The part of 'running hard cold'... thats common sense, also depends on what 'cold' means in your part of the world.
As for the wear damage by not waiting for the oil to start flowin? I dont really know, i've never started a car without waiting for the 'flow' and so far i've never ever had a problem due to wear damage... i think
You start the car, wait 30sec for the oil to get flowing, off you go. The part of 'running hard cold'... thats common sense, also depends on what 'cold' means in your part of the world.
As for the wear damage by not waiting for the oil to start flowin? I dont really know, i've never started a car without waiting for the 'flow' and so far i've never ever had a problem due to wear damage... i think
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09-30-07, 10:40 AM
#9
There can only be One
I 99% of the time warm up my car. Summer or Winter. I let that temperature gage get to normal operating temperatures before pulling out of my garage or from work.
Sometimes I just need to go so I just turn on and go but you can really see the difference and feel the difference when you just turn it on and go. And when I do that I don't even go over 4,000 RPM till it gets to regular operating temps.
Sometimes I just need to go so I just turn on and go but you can really see the difference and feel the difference when you just turn it on and go. And when I do that I don't even go over 4,000 RPM till it gets to regular operating temps.
09-30-07, 11:13 AM
#10
Lexus Fanatic
Don't just start a cold engine and let it idle without moving until it is at normal temperature. Let it idle until the oil pressure comes up.....that will take from about 10 to 30 seconds depending on outside temperature, engine condition, oil viscosity, and oil type...synthetic or petroleum. In really cold weather, without a block heater, you may want to let it idle for about two minutes or so to make sure the oil is warm enough to be flowing freely.
Then take off and drive GENTLY (below about 3000 RPM or so) until the coolant temperature is about 140 degrees or so...roughly the lower mark in the normal zone on the temp gauge. An engine is considered warmed up at 140 degrees, and can then be driven harder, though the thermostat usually doesn't open till about 195-200, and the cooling fan clicks on a little higher than that.
You guys are also forgetting about the transmission and differential fluids. THEY have to warm up, too. Letting an engine sit still while it warms up does NOTHING for those fluids to help THEM warm up. The best thing is to just drive slowly and gently for the first couple of minutes, warm ALL the drivetrain fluids up at once, and then drive normally.
Most engines, by actual testing, warm up more quickly and efficiently under a light driving load than when sitting still....and, of course the transmission and differentials heat up as well.
This, of course, refers only to normal, traditional gas and diesel engines. With Gas/Electric Hybrids, of course, the computers determine when the gas and electric motors cut on and off......which, of course, is determined by a number of factors relating to temperature, engine load, and state of battery charge.
Then take off and drive GENTLY (below about 3000 RPM or so) until the coolant temperature is about 140 degrees or so...roughly the lower mark in the normal zone on the temp gauge. An engine is considered warmed up at 140 degrees, and can then be driven harder, though the thermostat usually doesn't open till about 195-200, and the cooling fan clicks on a little higher than that.
You guys are also forgetting about the transmission and differential fluids. THEY have to warm up, too. Letting an engine sit still while it warms up does NOTHING for those fluids to help THEM warm up. The best thing is to just drive slowly and gently for the first couple of minutes, warm ALL the drivetrain fluids up at once, and then drive normally.
Most engines, by actual testing, warm up more quickly and efficiently under a light driving load than when sitting still....and, of course the transmission and differentials heat up as well.
This, of course, refers only to normal, traditional gas and diesel engines. With Gas/Electric Hybrids, of course, the computers determine when the gas and electric motors cut on and off......which, of course, is determined by a number of factors relating to temperature, engine load, and state of battery charge.
Last edited by mmarshall; 09-30-07 at 11:27 AM.
09-30-07, 01:27 PM
#12
09-30-07, 09:18 PM
#14
Tech Info Resource
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The 2IS forum has a massively long thread about this very subject.
It's foolish to idle for extended periods, and that's what you're doing by idling to warm up. Idling is fundamentally bad for an engine - oil pressure is at its lowest, and scavenging the air inside the engine to reduce the acidic byproducts of combustion is also at its lowest. The cam drive is getting severely abused regardless of whether it is belt or chain because the cams are turning slowly and loading/unloading the cam drive with each revolution - as rpm climb, this is less of an issue - if you read MANY recommended service guides you'll see timing belt replacement at shorter intervals when the engine idles alot (police and taxi service) just for this reason.
Only an idiot runs a cold engine hard (more than 50% throttle), but running at moderate throttle with light acceleration warms up the engine quickest.
Ideally you'd have an oil temperature gauge to tell you when your oil has reached 180F (ideal operating temp according to the API) so you'd know when you can give it full throttle without worrying about oil failures. BMW were doing this on the M5 in recent history with a variable red line based on oil temperature.
It's foolish to idle for extended periods, and that's what you're doing by idling to warm up. Idling is fundamentally bad for an engine - oil pressure is at its lowest, and scavenging the air inside the engine to reduce the acidic byproducts of combustion is also at its lowest. The cam drive is getting severely abused regardless of whether it is belt or chain because the cams are turning slowly and loading/unloading the cam drive with each revolution - as rpm climb, this is less of an issue - if you read MANY recommended service guides you'll see timing belt replacement at shorter intervals when the engine idles alot (police and taxi service) just for this reason.
Only an idiot runs a cold engine hard (more than 50% throttle), but running at moderate throttle with light acceleration warms up the engine quickest.
Ideally you'd have an oil temperature gauge to tell you when your oil has reached 180F (ideal operating temp according to the API) so you'd know when you can give it full throttle without worrying about oil failures. BMW were doing this on the M5 in recent history with a variable red line based on oil temperature.
