Warming up the engine on cold starts

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V
Cx-5 Sport
The best way to warm the engine before driving is with electric preheaters. Extended idling doesnt raise the temp as much as low speed driving. I have read that extending the time the engine operates at lower temps is harmful.

My ultra gauge takes some time to show water temp but the Catalytic Temp shows several hundred degrees in a minute or two. The cat gets hotter with higher speed driving on the highway because it is affected by how much fire is in the engine.

I think there is enough idling just buckling up and backing out. etc.
I dont need to intentionally sit and idle. I just drive with a light foot and keep the RPM fairly low for several minutes.

It probably takes 10-15 mins on the highway for the engine along with the rest of the drivetrain to get in the normal operating temperature range so I keep that in mind.
 
V
CX5 GT-R
Here in the northeast its been getting colder and colder lately and have noticed that the blue light for cold engine is on a lot longer than usual. As expected, it does take a lot longer to have warm air coming out the vents as well as high RPMs and limited power when accelerating.
How long do you guys wait until driving when you start the car from a cold start in the mornings?
Until rpm drops below 1000.
 
V
2017 Mazda CX-5 Grand Touring
If I am in the garage, I wait for the RPM's to drop to 1000. If the car is parked outside, I remote start and let it run for a few minutes (depending on the temps outside). So far, so good.
 
V
Mazda CX-5 GTR 2019
When walking my dog in the morning I am often greeted by the sight of driverless cars, sitting in driveways, engines running. This seems to start with temps no colder than 50 degrees F. Always makes me shake my head how people seem unable to accept new information. Unless below freezing, there is no need to warm up your car with fuel injection. And, even then, just a minute or so.

https://www.popularmechanics.com/cars/car-technology/a19086/warming-up-your-car-in-the-cold-just-harms-engine/

https://www.roadandtrack.com/car-culture/videos/a30249/why-you-shouldnt-warm-up-your-car/

Tim
 
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V
2018 CX-5 Sport
I let mine idle until the rpms drop, a minute or two. I don't like putting it in gear if the idle is high. Then I accelerate like a grandma until it reaches normal operating temperature.
 

Avoidin Deer

Central Virginia
Contributor
V
2019 CX-5 Reserve
This is also what I do, regardless of outside temps. Never any good to put an AT in gear w/ the RPMs way up.
Yup.

Gotta love watching someone start up a vehicle on a freezing cold day and immediately putting it in Drive so the body lurches on the suspension.
 

Avoidin Deer

Central Virginia
Contributor
V
2019 CX-5 Reserve
Some of the stuff in these articles bear quoting:

Engines with electronic fuel injection have sensors that compensate for the cold by pumping more gasoline into the mixture. The engine continues to run rich in this way until it heats up to about 40 degrees Fahrenheit.

"That's a problem because you're actually putting extra fuel into the combustion chamber to make it burn and some of it can get onto the cylinder walls," Stephen Ciatti, a mechanical engineer who specializes in combustion engines at the Argonne National Laboratory, told Business Insider. "Gasoline is an outstanding solvent and it can actually wash oil off the walls if you run it in those cold idle conditions for an extended period of time."
So the Mazda manual's instructions to let the car warm up for 10 seconds (to build up the oil pressure) and then start driving (to warm it up faster so the ECU leans out the fuel mixture sooner) seem to be good advice...and might reduce the chances of oil dilution.
 
V
2014 Mazda CX-5 Touring AWD
99% of the time, I drive off immediately after the RPM drops, ~20 seconds or so. I drive gently until the blue light turns off. I don't turn the heater on right away (if at all), I wait a little for the engine to get warmer first.
The rest of the time, I either start driving before the RPM drops, or until I have cleared the windows of snow.
 

Chocolate

Harpy Eagle
V
2019 Mazda CX-5 AWD
We 2019 owners don't have the light. Instead the first 1/2 inch of the temp gauge has blue markers to denote a cold engine.
Mine has it. I guess the digital speedo is different. The Sport/Touring (plebeian editions) come with a smaller LCD to the right of the speedo.
 

Chocolate

Harpy Eagle
V
2019 Mazda CX-5 AWD
Some of the stuff in these articles bear quoting:



So the Mazda manual's instructions to let the car warm up for 10 seconds (to build up the oil pressure) and then start driving (to warm it up faster so the ECU leans out the fuel mixture sooner) seem to be good advice...and might reduce the chances of oil dilution.
15-30 seconds is fine, especially in normal temperatures.
Warming up vehicles is a thing in freezing climates during winter.
I've never done it in winter, but I will say it is a gigantic pain in the ass to scrape ice off the windshields and windows, so I understand why people do it.
 

Avoidin Deer

Central Virginia
Contributor
V
2019 CX-5 Reserve
15-30 seconds is fine, especially in normal temperatures.
Warming up vehicles is a thing in freezing climates during winter.
I've never done it in winter, but I will say it is a gigantic pain in the ass to scrape ice off the windshields and windows, so I understand why people do it.
Agreed. You gotta get the defrosters warmed up.

I have Rain X on my windshield, and the only scraping I've done so far doesn't seen to have been made any easier.
 

7eregrine

The man, the myth, the legend
L
Land of Cleve
V
2016.5 CX5
I certainly don't buy into the notion that letting a car idle and warm up for 10 minutes is all that detrimental. If idling is that bad for a car then we are designing cars wrong. Yes, i of course agree a car warms up faster under load. That's an irrefutable fact. But letting it run in the driveway for 10 minutes isn't shortening it's life either.
 

Avoidin Deer

Central Virginia
Contributor
V
2019 CX-5 Reserve
I certainly don't buy into the notion that letting a car idle and warm up for 10 minutes is all that detrimental. If idling is that bad for a car then we are designing cars wrong. Yes, i of course agree a car warms up faster under load. That's an irrefutable fact. But letting it run in the driveway for 10 minutes isn't shortening it's life either.
I've always warmed carburetor engines up for extended periods of time. But Honda claims that it's oil dilution problems are worse in cold weather. I gotta think this is why.

I agree that if idling is that bad for a car then we are designing cars wrong. I think Direct Inject is a bad design.
 

sm1ke

Work In Progress..
Moderator
Contributor
L
Canada
V
'18 CX-9 Signature
I certainly don't buy into the notion that letting a car idle and warm up for 10 minutes is all that detrimental. If idling is that bad for a car then we are designing cars wrong. Yes, i of course agree a car warms up faster under load. That's an irrefutable fact. But letting it run in the driveway for 10 minutes isn't shortening it's life either.
Here's a short video from Engineering Explained. Pretty concise explanation from an actual engineer, with nice visual aids. It would be better if I had actual studies to cite, but I'm personally not invested in the topic enough to do any further research.

 

7eregrine

The man, the myth, the legend
L
Land of Cleve
V
2016.5 CX5
I've always warmed carburetor engines up for extended periods of time. But Honda claims that it's oil dilution problems are worse in cold weather. I gotta think this is why.
I think that's because of the same reason some Saabs had sludge issues: not letting the car get up to proper operating temperature.

I will watch your video sm1ke, but I doubt anything can change my mind. I've done buckets of internet 'research' and my own experience tells me: it's ok to let a car idle a bit.
 
V
Cx-5 Sport
I wonder if low speed operation worsens valve contamination on DI engines.

It is one thing to idle after the engine is warm but idling when cold extends the time the engine wears the most.

My manual says after starting to idle for 10 seconds.

I can understand why some want to warm up in frigid temps. I hardly doubt it will ruin the engine. It might trigger the flexible oil change reminder to change the oil sooner. I think it is good to change the oil in March or April regardless of the OLM.
 

Kedis82ZE8

i-ACTIV AWD Aficionado
Contributor
V
'15 CX-5 GT AWD w/tech
I think that's because of the same reason some Saabs had sludge issues: not letting the car get up to proper operating temperature.

Most engine sludge issues I have seen are the result of extreme maintenance neglect or an inherent lubrication design flaw in the motor.
 
V
2014 Mazda CX-5 Touring AWD
I certainly don't buy into the notion that letting a car idle and warm up for 10 minutes is all that detrimental. If idling is that bad for a car then we are designing cars wrong. Yes, i of course agree a car warms up faster under load. That's an irrefutable fact. But letting it run in the driveway for 10 minutes isn't shortening it's life either.
Based on the facts, letting a car idle to warm up takes longer than light driving it. This means you extend the cold operation of the engine which means internal wear is increased. It is not like you destroy the engine after a single occurrence, but over multiple years, you do shorten your engine's life. No way around that. You might not care, if you get rid of it before the troubles start.
Further more, if the engine does warm up to good operating temp while idling, the transmission will remain cold. It too needs to warm up. If you now drive the car hard (as the engine is all warmed up), you may be causing even more wear.
 

Avoidin Deer

Central Virginia
Contributor
V
2019 CX-5 Reserve
So if the cold-rich-running washes away the oil from the cylinder walls, how much more damage might be cause by putting the cold engine under load (as the oil continues to get washed off the cylinder walls), just in an effort to warm it up faster to make it run lean (and be properly lubricated sooner)?

Wouldn't under-load/poorly-lubricated short driving be just as bad as no-load/poorly-lubricated extended idle?

I'm now wondering if the difference between the two is negligible.
 
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