Warming up an engine

[SteveSRT8]

I also see the neighbors doing the long warmup thing, in FL no less!

It's crazy, just keep your foot out of it and go easy for a few minutes. No big deal.

"warm up" is a lot like "break in". Obsolete terms for newer cars.

 

[demarpaint]

I don't think a long warm up is necessary however, its not a good idea to release a clutch when an engine is running over 1700 rpm on a fast idle because its cold out. Putting a car into drive or reverse when an engine is racing isn't a good idea, or waiting for a light with an AT in drive at a fast idle. Waiting for the rpms to drop to 1000 seems to be a level I'm comfortable with, and it doesn't take that long. Opinions vary.

 

[ZZman]

Anything more than a minute is a waste of good fuel. Idling means 0 gas mileage. I decent oil at a reasonable temp is going to flow fine.

How can cold oil in the pan flow better by idling for a while to let the block get warm? It flows now or it doesn't.

 

[demarpaint]

As long as its not slamming into gear, or burning up a clutch on take off that's good enough for me.

 

[yeti]

I idle for at least a minute and then start my drive through the neighbohood which takes 5 minutes. It's perfect because it puts a slight load on the engine which warms it up faster but it's a very small load with low rpms.

The biggest factor is to keep the heater off and temperature setting at cold until the water is up to temp. Without the extra water circulating, it warms up over twice as fast. buick gn.

exactly as i've always done.

 

[sciphi]

I wait 10 seconds, then drop into D and go. My commute is all city and uphill, so the engine has a moderate load on followed by periods of idling. I also drive it gently for the first 10 minutes.

Other people in my family turn their cars on and floor it out of the driveway. Even in sub-freezing weather.

 

[2003f7]

I do let my car warm up for 10 or 15 minutes here in the Wisconsin winter when the temps can get as low as -20F. I would rather idle the car than put my young son in a cold car. The long idle times and short trips are the reason I change my oil based on months not miles.

 

[Gary Allan]

Originally Posted By: Steve S
Believe it.



The 90% of wear at start up is a marketing term stolen from the definition of start up being anything other than steady state. The wear follows a decreasing curve with reaching full operating temp. Most engines do not operate outside of start up (about 20 minutes) ..so I imagine that you don't even have to measure ..but take a survey of how many engines operate over 20 minutes per event vs. how many do and get the same 90% figure.

That is, an engine that only operates 15 minutes per cold start event ..and every event is a cold start event (that may be 75F+) has ONE HUNDRED PERCENT OF ALL WEAR AT START UP.

 

[Max_Wander]

Originally Posted By: Gary Allan

That is, an engine that only operates 15 minutes per cold start event ..and every event is a cold start event (that may be 75F+) has ONE HUNDRED PERCENT OF ALL WEAR AT START UP.


Thats hilarious when you put it that way

In the Camry, I just choose an oil that reduces/eliminates the piston slap at cold load, that way there's nothing to cringe at when it's driven off 15 seconds after startup. I dont like warming engines up for more than a minute unless I know it's very cold and there is very thick oil in the crankcase. Maybe they like to use 20w50 and thicker in Kuwait... surely they couldnt care less about mileage!

 

[demarpaint]

Originally Posted By: Gary Allan
Originally Posted By: Steve S
Believe it.



The 90% of wear at start up is a marketing term stolen from the definition of start up being anything other than steady state. The wear follows a decreasing curve with reaching full operating temp. Most engines do not operate outside of start up (about 20 minutes) ..so I imagine that you don't even have to measure ..but take a survey of how many engines operate over 20 minutes per event vs. how many do and get the same 90% figure.

That is, an engine that only operates 15 minutes per cold start event ..and every event is a cold start event (that may be 75F+) has ONE HUNDRED PERCENT OF ALL WEAR AT START UP.


Then a car driven in cold climates to and from work running for 15 minutes each way, that has logged 100,000 miles would have ~ the same wear as an engine that has 1,000,000 miles? That's what the marketing people would want us to think isn't it? . OOPS my math could be wrong because of the decreasing curve, maybe the number is 750,000 miles?