Warming up the engine

And prevents you from waiting for the overdrive to work.

 

I'm just doing some educated/common sense thinking out loud here: what about the notion that running a high idle while in neutral is bad for the engine. I've been told before that revving an engine is harmful for the car. My take away from that was if you are going to go high RPMs it should be when in gear.

That's really my main concern when warming up my Yota. The engine is sitting there in neutral with the RPMs above normal for basically the whole time.

 

This. Sit about 30 seconds or so, then start driving normally without any engine racing to get the engine to operating temp.

 

the one thing you can do it use lighter oil in winter months, I just did a change last month to 0w30 Synthetic cause I won't be changing until the spring. The 0 promotes easier flow upon startup but it is still 30 weight viscosity for when you're running at normal engine temps.

the whole idea of letting the vehicle idle is a personal preference and you can't change some peoples minds. Yes, it is nice to get into a warm vehicle, but it will warm up just fine after you start moving. Since more parts are moving causing friction the heat will populate faster.

Your local area or municipality will also have regulations for idling (not just for big trucks) due to EPA emissions. An idling vehicle produces more emissions (and less MPG obviously) and there are now many places where you will receive citations if caught (CA anyone?).

 

Your engine needs a load to warm up quickly and efficiently. Just revving does not produce a load so warm up takes longer, producing more wear than simply driving.

 

"he needs to start going to bed 10 minutes before you do, to
warm up the bed for you on cold winter nights. That's a warm-up
activity he can do that's actually useful!"

I had to at that! I miss those guys!

 

It's personal preference. As long as you don't just jump in and floor it, the difference is negligible. Like the whole 'leave it first at a stop light' vs 'put in in neutral' debate.

Here's what I do when it's cold: get in, start the truck, get out, scrape off all the ice and such (a minute or two), get back in, take it easy for a few blocks, then I get on the highway and by then it's fine and I just drive it.

 

I don't know the answer to this, but has anyone ever wore out an engine because they warmed it up too long? I just can't see the harm in letting it idle for however long you want before driving. Living in Alaska, Colorado, Missouri, and Germany where it got cold at times, I let it warm up as needed. As far as I know I never had any issue related to a warm engine. Those tires with the flat spots were another issue though.

 

I would rather warm it up then listen to my engine scream at me in -40 driving down the block

 

I know a guy who came home and left his car on in the driveway... overnight. I guess he intended to come back out and got distracted then forgot? Anyways, his car was fine.
But really, driving a car in any condition will cause it to wear out... so will not driving it. As long as you don't do anything stupid like immediately redline it and dump the clutch, I figure your engine is probably fine either way.

 

The amount of gas you're "wasting" while it's running rich during warmup: I challenge you to notice a difference in your overall gas mileage between letting it sit for a minute vs. driving it before it's fully warmed up.

Plus, it's going to run rich during warmup no matter what, so you are actually using MORE gas when driving it rich (not idling), than letting it sit in the driveway for a minute (at idle) while it warms up.

Just don't start it up and throw it in gear right away, at least give it 30 seconds or so for the fluids to start moving to where they're supposed to be. As others have said, the problem isn't the temp of the oil (you should be running an appropriate winter viscosity anyway), but that it's all settled to the bottom of the engine.

Just start it up, crank the heater and let it sit for a minute or two while you scrape the ice/snow off the windows. Not only will your engine be at/near operating temperatures, your hands won't freeze to the steering wheel when you get in, and your windows will be defogged.

 

Well yeah, don't sit in the driveway and pound on the go-fast pedal to get it to "warm up faster". That's stupid.

But the engineers designed the engine systems to work properly, and give the best reliability possible. Part of that is a slightly higher rev and rich mixture during warmup.

You're over thinking this.

 

This is similar to the preload or not to preload the oil filter debate

 

that really only applies to diesels and heavy machinery where the oil filter holds 3 liters of oil on its own. 200mls in a tiny ass taco filter isn't going to change anything.

 

I think that idling when cold is worse for the motor because there is lower oil pressure at idle, and since there is no load, it has to idle at low oil pressure for a long time to get hot. I start it, idle for 20-30 seconds, then drive gently at 2000 rpm or so until it's hot.

 

I went from 13 to 9.5 on the next tank when I let it warm up for a couple minutes during 0° - 10°. I stopped letting it idle and just drove slow. Started before I put my coat on and then started out when I got to the truck (30-45 seconds).

also, just letting it idle and then only going shorter distances leaves moisture in the exhaust pipes that does not get expelled or evaporated and could cause earlier rust.

 

There are too many variables that contribute to gas mileage to be able to tell, but driving style is by far the biggest. You driving slow is more likely what caused your increase in mileage...

The relative change in mixture ratios (which are relatively small, maybe 14:1 to 11:1 (I'm guessing), given the total volume of gasoline in a tank, and the very short amount of time the mixture is high, means that is a very small contributor to overall mileage. Like extremely small.

 

That is incorrect. Cold oil is thicker which is harder to push through the tight tolerances of main and connecting rod bearings. Don't believe me? Put a mechanical oil pressure gauge on and start the engine when it's cold, oil pressure will be very high until the oil temp comes up.
You should always allow your engine to warm up( When it's safely to do). Your engine will love you for it in the long run.
Also when the engine is cold, the ECM riches the fuel mixture to heat up that Catalytic convertor quickly to reduce emissions and not to quickly heat up the engine.

 

I'm also high desert @ 5500'. And this is what I do. Here it's 20-100 degrees throughout the year. Not to temperature dramatic..
In summer I let it warm up 3 minutes and 5-6 in the winter.
Just did an extended oil run @ 7k. Up from my usual 3-5k runs. We'll see what Blackstone has to say about it next week.

We can all argue here... But science ftw.

 

same drive to work, same route. only difference was letting the engine warm up so my butt wasn't cold.

Driving slow is actually better for gas mileage as it keeps the engine in the ideal rpm range (1500-2000). Also I keep O/D off below 45 mph no matter when or where I drive.