Exactly Why You Need To Warm Up Your Car When It's Cold

[KawBoy]

https://www.msn.com/en-us/autos/owne...cid=spartandhp

[STooK]

So it's a good idea to let it run a couple minutes before take off? I usually let it run 30 seconds then drive slowly afterwards. Seem to work pretty well.

[dparm]

Jesus Christ, this fucking article.

Warming up a car is literally one of the worst things you can do. How many goddamn times does this myth have to be brought back to life? Oh right, it's by Jalopnik.

[KawBoy]

I always put some heat before taking off. Even in Florida.

[KPop]

Since my M3 isn't a daily driver, I always start it up and wait until the cold-start high idle is finished before pulling it out of the garage. Regardless of the air temperature outside, I always drive it conservatively and shift under 3k RPM until I'm given the all clear by the variable redline and the oil temp gauge reads around 200 degrees. I'm not in any rush to get anywhere when I drive this car so I like taking my time. It's like a ritual, of sorts.

[jeddo45]

Originally Posted by dparm

Jesus Christ, this fucking article.

Warming up a car is literally one of the worst things you can do. How many goddamn times does this myth have to be brought back to life? Oh right, it's by Jalopnik.

Why? Curious to know if letting your car warm up is really bad for a car...

[Bartledoo]

Originally Posted by jeddo45

Why? Curious to know if letting your car warm up is really bad for a car...

I think he meant warming it up by letting it sit idling.

[srmast1]

Originally Posted by ksteckba

I think he meant warming it up by letting it sit idling.

Why is that bad for your car mechanically? Besides fuel use and emmissions of course, which don't hurt the car.

[romemmy]

You want to get a car up to temperature as quickly as possible so that the AFR leans out. When you first start the car cold it will run rich, and as the engine warms, it leans out. Running rich is not great for engines as it can lead to bore wash (where excess fuel, which is a great solvent, literally washes the cylinder bore of oil).

IMHO, modern engines need very little cold start idle - 30secs is typically plenty. Driving it gets the temps up quickly, leaning out the mixture, and gets to ideal AFR as quickly as possible.

Thanks!

S.

[nrubenstein]

Also, at idle, oil pressure is very low. Running the engine at moderate loads will get oil circulating better.

Net-net, there is no benefit to idling the car up to temperature. That said, there isn’t a lot of harm in it, either. I’ll freely admit that sometimes I warm cars up for my own comfort. But that’s for my comfort, not because it’s good for the car.

[BrewRifle]

I usually wait until the cold cycle finishes ~ 1 minute before backing out.

[dparm]

Originally Posted by srmast1

Why is that bad for your car mechanically? Besides fuel use and emissions of course, which don't hurt the car.

Because engine load will warm the engine up, not idling. At idle there is basically zero load. All you are doing is trying to pump cold, thick oil through the engine. By sitting there for a few minutes, you're taking what could be just 10-15 seconds of cold start wear and stretching it out. The article alludes to this but then jumps all over the place on stupid tangents. It reads like an absolute mess.


For the umpteenth time, this is how to drive a car in cold weather:

1. Start the car
2. Wait a few seconds
3. Drive away
4. Keep engine load low until the oil temperatures have risen

If you are very concerned about cold start wear, and/or routinely drive your car in extremely cold temperatures, you can consider something like an engine block heater, oil pan warmer, Accusump, or some combination of the three.

[shimmy23]

Originally Posted by BrewRifle

I usually wait until the cold cycle finishes ~ 1 minute before backing out.

I do this. If I drive off while the car is in cold start phase it drives like the throttle is stuck open

[NoHedge]

Originally Posted by dparm

Because engine load will warm the engine up, not idling. At idle there is basically zero load. All you are doing is trying to pump cold, thick oil through the engine. By sitting there for a few minutes, you're taking what could be just 10-15 seconds of cold start wear and stretching it out. The article alludes to this but then jumps all over the place on stupid tangents. It reads like an absolute mess.


For the umpteenth time, this is how to drive a car in cold weather:

1. Start the car
2. Wait a few seconds
3. Drive away
4. Keep engine load low until the oil temperatures have risen

If you are very concerned about cold start wear, and/or routinely drive your car in extremely cold temperatures, you can consider something like an engine block heater, oil pan warmer, Accusump, or some combination of the three.

Also wanted to add that idling will not warm up the transmission. This can potentially cause problems if one pushes the car when the motor is up to temp before the tranny.

[dparm]

Originally Posted by NoHedge

Also wanted to add that idling will not warm up the transmission. This can potentially cause problems if one pushes the car when the motor is up to temp before the tranny.

Correct. The transmission and rear differential will take longer. They are also fairly thick fluids which is why things always seem clunky when it's cold.

[Richbot]

I died several times this year already because I didn't warm my car up before leaving, with these cold temperatures you'll die a lot



gearboxes warm up via friction like most anything else in a car...letting them sit still without moving doesn't warm them up unless they have a cooling loop on a common heat exchanger with the engine. there's virtually no heat transfer from bell housing to the gearbox itself. That article is almost as awesomely bad as the HUGE NUM BER OF WARMING UP CARS THREADS WE HAVE ON HERE PLEASE DELETE THEM ALL KTHNXBYE

[cgoldie187]

I usually just wait for the idle to come down to normal levels. I was in a huge rush the other day, drove off about 5 seconds after starting the engine. You could tell the car did not like it, it was very choppy and kept holding the high idle when I can to a stop about a 30 seconds later.

[burtonsbs5114]

Like most of the above, I want for the RPMs to chill and then slowly drive off until oil comes up to temp.

[spazzyfry123]

My morning ritual:

1) Open door into the garage and push button on the wall to open the actual garage door.
2) Get in car.
3) Start car.
4) Put on seat belt.
5) Put car in 1st.
6) Go to work.

From opening the garage to pulling it out of the garage is about 15 seconds. I shift around 3k - 3.25k until I'm up to temp. I generally get up to temp once I'm at the on-ramp for my highway commute. And then I let her rip!

[Duk996]

Originally Posted by spazzyfry123

My morning ritual:

1) Open door into the garage and push button on the wall to open the actual garage door.
2) Get in car.
3) Start car.
4) Put on seat belt.
5) Put car in 1st.
6) Go to work.

From opening the garage to pulling it out of the garage is about 15 seconds. I shift around 3k - 3.25k until I'm up to temp. I generally get up to temp once I'm at the on-ramp for my highway commute. And then I let her rip!

I usually start the car then keep the revs right in the yellow range for 15 minutes. It gets all the exhaust tubing nice and hot which straddles the engine, tranny, and diff so it all warms up nice.

By that time the engine oil is the right temp and there is no driving redline down time.

[ItsGary]

Originally Posted by spazzyfry123

My morning ritual:

1) Open door into the garage and push button on the wall to open the actual garage door.
2) Get in car.
3) Start car.
4) Put on seat belt.
5) Put car in 1st.
6) Go to work.

From opening the garage to pulling it out of the garage is about 15 seconds. I shift around 3k - 3.25k until I'm up to temp. I generally get up to temp once I'm at the on-ramp for my highway commute. And then I let her rip!

Almost same but

1) walk outside
2) get in car
3) put on seat belt
4) plug in aux to phone
5) windows down
6) start car
7) go wherever cause i dont have a job yet and i want one

[Spun Crankhub]

I pretty much short shift until the oil gauge hits the first line. Thats as close to warming up my car I get.