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Author Topic: Warming up the car Back to Topics
JamCoope

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Maryland

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Message Posted: Jan 26, 2011 10:21:52 AM

Most people agree that cars run more economically once they're warmed up... especially in the cold winter months.

Here's a question: has anyone tested whether it is more economical to let your car warm up by idling in the driveway, or by just letting warm up as you drive?
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Mininana
Sophomore Author New York

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Message Posted: Jan 28, 2015 3:47:21 PM

mininana's mininana prefers a warm car, so he often starts it one or two minutes before actual departure time, cracks the garage door a sliver and usually has the blue "cold" light off by back-off... don't know if this helps or hurts gas mileage, but can't imagine in either way it's enough to care about...
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b899
Champion Author Connecticut

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Message Posted: Jan 28, 2015 8:47:10 AM

no
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carinthuist
Champion Author San Francisco

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Message Posted: Jan 25, 2015 11:23:01 AM

no
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b899
Champion Author Connecticut

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Message Posted: Jan 25, 2015 8:47:52 AM

no
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Gabilondo
Champion Author New Mexico

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Message Posted: Jan 22, 2015 2:23:52 PM

I warm up my car in the winter, and I have noticed that winter fuel economy is worse than summer. So, I can make an assumption that it has to do with the idling.
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boybad12
Rookie Author Missouri

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Message Posted: Jan 21, 2015 11:38:28 PM

just long enough to start to feel some heat about 3 or 4 min.
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roadrunner7669
Champion Author Florida

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Message Posted: Jan 21, 2015 4:20:41 PM

yes, 10 mins
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b899
Champion Author Connecticut

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Message Posted: Jan 21, 2015 8:47:34 AM

no
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allout71
Rookie Author Maine

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Message Posted: Jan 21, 2015 6:45:16 AM

I warm my cars up for at least 5 min during the winter months! This is not for comfort but for safety!!! Windows freeze and fog up!
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drgeeforce
Veteran Author Los Angeles

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Message Posted: Jan 20, 2015 1:09:52 PM

In the MidWest and in the East, some autoparts stores sell a dipstick oil heater. You plug it with a 15A timer in your garage and set it for 1 hr before to leaving for work, I have had no issues with cold starts in subfreezing weather.
On my diesel, I have a 300 watt magnetic heater and only need 15mins. Electricity is far cheaper way to warm your engine than using gas.
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badbobKY
Champion Author Lexington

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Message Posted: Jan 20, 2015 11:41:28 AM

winter
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b899
Champion Author Connecticut

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Message Posted: Jan 20, 2015 8:51:35 AM

no
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dontuknowOH
Champion Author Ohio

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Message Posted: Jan 17, 2015 7:34:56 PM

Hemond; You are right, cavitation is a bit strong description for a centrifical impeller type automotive coolant pump condition.

About the small hole seen on some thermostats, I believe it's there to enable the coolant which is becoming heated to move toward the action element of the thermostat in order to heat caress it for a reaction by passing on by. There isn't that much pressure developed on the engine coolant out side when the thermo is closed.

Saying the tiny hole is a sensing vein in nature for the hotter lagging back coolant to reach the T-element for a reaction to start opening. Once that happens more hotter fluid will flow threw, after the thermo gets triggered.

One can tell if they hold their fingers at the top radiator metal/plastic neck as the engine is in warm-up fast idle mode, Tell when the thermo actually opens and starts letting coolant circulate.

CAUTION! Where the hands/fingers are placed near the radiator(moving fans/belts/pulleys)! Big Ouch!
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luvmyrv
Champion Author Winnipeg

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Message Posted: Jan 17, 2015 5:13:20 PM

at today's gas prices it makes it a little more appealing to let it warm up.
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Xue891
Rookie Author Sacramento

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Message Posted: Jan 17, 2015 3:36:37 PM

Just drive slowly to warm up is more efficient than wasting gas idling.
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Hemond
Champion Author Providence

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Message Posted: Jan 17, 2015 12:34:19 PM

QUOTE ::::: Still there must be somewhere a small amount of coolant circulation to prevent coolant pump cavitation near the pump seals to protect them,:::;


Thermostats have a provision for this. Either a small hole in the valve or some 'leakage' engineered in deliberately. This allows a minimum amount of coolant to circulate even while dead cold.

Theoretically cavitation is a concern. I've just never heard of it being of importance in automotive pumps. I've never observed it in an operating engine. It is most definitely a concern with large industrial pumps. Early in my career I dealt with large industrial pumps, 2000 hp and bigger. Cavitation is dramatic and unmistakable in sound. If a car's water pump was cavitating, you'd hear it clearly.
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moxxor54
Sophomore Author Missouri

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Message Posted: Jan 17, 2015 10:29:54 AM

Drive slow to get warm faster than idling on a driveway

My father in law used to warm up his trucks (gas) wat too long up 15 to 30 minutes. Between 50,000-60,000 miles, the engines started having problems. He complained why his trucks fell apart. I tried to warn him that long warm up caused the problems. He did not agree with me. This time was bewteen late 1970's-2010's. Now he does not warm up very long. I know he won't admit it LOL ! Just let him go. Smile
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dontuknowOH
Champion Author Ohio

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Message Posted: Jan 17, 2015 9:16:05 AM

My experience is that some vehicles have simple cabin heat systems that still let the engine coolant circulate that heater circuit path while bypassing the engines thermostat, when closed for engine warm-up. Even with an (OK Stat)working properly!

When very cold outside temps are the case, if the cabin heater blower is on a high speed setting, idling takes longer and consumes more fuel. The reason is that your heater core/high blower speed actually acts as an extra radiator and then is cooling the engine and Defeating the closed purpose of the thermostat during any(cold engine)warming period time. That varies with different vehicles/systems and Drivers choices......

Some vehicles have more elaborate cabin heat systems that prevent coolant circulation (bypass) in the heater circuit. Still there must be somewhere a small amount of coolant circulation to prevent coolant pump cavitation near the pump seals to protect them, also preventing hot spots within the engine blocks/cylinder heads as the engine warms to normal operation (thermostat regulated) engine temps.

You may have heard of engine failure due to warped heads/gasket failure, and antifreeze into the engine oil along with overheat damage problems. there are many causes/many and many preventive solutions, with regard to CEL being lit Minor/major is waiting for your greens $$$ some(exceptions).
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twt
Champion Author Virginia Beach

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Message Posted: Jan 17, 2015 5:40:20 AM

A total waste, of fuel. Your engine will warm up after driving for five to eight minutes. If not, you need to change the thermostat.
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Hemond
Champion Author Providence

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Message Posted: Jan 17, 2015 12:21:10 AM

QuoTE::::::It is not good to let your cold car just sit and idle because the oil pressure is lower and it flows in the same pattern.::::


This comment is pure nonsense.
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RacksnSpurs
Sophomore Author Raleigh

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Message Posted: Jan 16, 2015 9:20:32 PM

What xtremecheap said.
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xtremecheap
Champion Author Arkansas

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Message Posted: Jan 16, 2015 8:13:21 PM

It is not good to let your cold car just sit and idle because the oil pressure is lower and it flows in the same pattern. It's better to drive very mildly until warm, or the best for the engine is to fluctuate the rpms between 1-2.5k while parked until warm.
I understand most people do not want to sit in a cold car revving it up and down waiting for it to warm up, and I don't blame them. It's just not the "best" thing to do.
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juniperus98
Rookie Author Alberta

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Message Posted: Jan 16, 2015 5:29:36 PM

its better to drive the vehicle than to let it idle.
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LibertyGuardian
All-Star Author Arizona

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Message Posted: Jan 16, 2015 8:51:49 AM

Whether economical or not, I want our vehicles comfortable when we get in them to drive somewhere and have no issue wasting whatever miniscule amount of fuel it takes to do so.
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b899
Champion Author Connecticut

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Message Posted: Jan 16, 2015 7:58:44 AM

no
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Hemond
Champion Author Providence

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Message Posted: Jan 15, 2015 11:03:27 PM

I keep mine idling even during stops. Tonight I briefly stopped at a bud's house and went inside. I left it idling outside. So little gas is used idling that I don't ever worry about it. No logical reason to avoid idling. (other than theft perhaps, that is a reason not to let it idle unattended.)
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skaboss79
Sophomore Author New Mexico

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Message Posted: Jan 15, 2015 11:57:21 AM

right now it's cold as hell so yea warm it up to get the heated seats nice and ready :)
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badbobKY
Champion Author Lexington

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Message Posted: Jan 15, 2015 8:39:20 AM

winter-time
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b899
Champion Author Connecticut

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Message Posted: Jan 15, 2015 8:33:00 AM

no
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46chief
Champion Author Indiana

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Message Posted: Jan 14, 2015 3:50:23 PM

Only 30 seconds or so.
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dontuknowOH
Champion Author Ohio

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Message Posted: Jan 14, 2015 8:16:46 AM

Mainly 30 seconds, then moving away, or 1.5 ---3 minutes depending on the Winter conditions. I have reasonable heat at the vents as soon as the RPMs drop to 900 engine revs. No remote start yet! One .5 minutes is the usual.
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twt
Champion Author Virginia Beach

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Message Posted: Jan 13, 2015 5:32:01 AM

A waste of fuel. The engine will warm up within five minutes, while driving.
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Hemond
Champion Author Providence

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Message Posted: Jan 13, 2015 2:24:23 AM

::::No. Not even sure how one would test for that to get reliable data.:::


Simple. Use an automotive computer which taps into the OBDII port. They are cheap now. Some use the phone as a display. I use an old school Scan Gauge, but the phone apps have a better display and more data.
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ccnpkid
Rookie Author Chicago

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Message Posted: Jan 12, 2015 10:23:47 PM

yes i hv done
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Heavyblaze
All-Star Author Pennsylvania

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Message Posted: Jan 12, 2015 7:50:40 PM

only for a few minute when cold out
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Tanner_1
Champion Author Virginia Beach

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Message Posted: Jan 12, 2015 4:18:04 PM

No. Not even sure how one would test for that to get reliable data.
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b899
Champion Author Connecticut

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Message Posted: Jan 12, 2015 7:53:42 AM

no
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cv
Champion Author Raleigh

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Message Posted: Jan 11, 2015 7:14:02 AM

I just do a brief warm up until the oil pressure gets normal.
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shigh2001
Sophomore Author Washington

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Message Posted: Jan 8, 2015 3:39:03 PM

Luckily I park in an garage, so I don't have this problem anymore :-)
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hoopitup2000
Champion Author Virginia

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Message Posted: Jan 8, 2015 6:54:10 AM

Very tempting this morning @ 7°, but only 15 seconds since the windows were clear. Cold enough this morning to trigger the TPMS light. (Brrrrrr)
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mybigtruck
Champion Author San Jose

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Message Posted: Jan 8, 2015 1:54:56 AM

it takes forever to warm up a diesel, esp idling. (diesels are far more efficient than gas engines...by definition) I just start driving like a gramps a few seconds after oil pressure is up

[Edited by: mybigtruck at 1/8/2015 1:55:48 AM EST]
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Hemond
Champion Author Providence

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Message Posted: Jan 7, 2015 8:28:24 PM

11 degrees right now. I'm going out in a few minutes. I'll warm it up first. Its stupid to sit in a cold car.
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PhilnTX
All-Star Author Dallas

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Message Posted: Jan 7, 2015 5:57:17 PM

On cold days, I'll start it up and let the seats warm up.
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WilhamClouse
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Message Posted: Jan 7, 2015 2:37:45 PM

Maybe a minute, but it warms up better by driving.
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94Rod
Rookie Author Orlando

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Message Posted: Jan 7, 2015 11:23:29 AM

I start driving right away, just slowly. I'll speed up once the car is sufficiently warmed up.
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hoopitup2000
Champion Author Virginia

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Message Posted: Jan 7, 2015 6:35:56 AM

Only if the windows won't stay clear.
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lilmx5guy
Sophomore Author Scranton

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Message Posted: Jan 6, 2015 6:49:12 PM

Only when it's really cold out.
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b899
Champion Author Connecticut

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Message Posted: Jan 5, 2015 7:44:34 AM

no
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dontuknowOH
Champion Author Ohio

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Message Posted: Jan 3, 2015 11:24:15 AM

When its really cold and My vehicle has sit outside, I treat it like a 3 minute red light, trying to not be such a cheap ass-essory to my vehicle. Pardon my spelling. But I understand that V/6 and V/8 power plants do use or rather waste amore fuel doing the extra idling @ 0 mileage.

One can't have both comfort and always save every drop of their fuel, so have at it, what you can afford is My motto.... It works for me anyway!

It is much worse idle warming then shutting the vehicle off for a change of the mind, I've know of individuals doing that before. Usually afraid to drive after cleaning the car off. Maybe a Black cat crossed their snow path?
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Shockjock1961
Champion Author Illinois

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Message Posted: Jan 3, 2015 11:03:41 AM

I'd rather waste a teaspoon or so of fuel then risk causing an accident.
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twt
Champion Author Virginia Beach

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Message Posted: Jan 3, 2015 3:27:08 AM

A waste of fuel.
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