Warm up time

[ayau]

Note that warming up the engine doesn't mean the transmission is warmed up. When you idle your car until your engine is "warm", the transmission isn't at operating temp yet. You still need to take it easy until the transmission is warmed up.

The same thing for the differential. You need to drive it to warm it up.

This is what I do.

Start the car.
Wait about 10 seconds.
Drive slowly (stay below 2.5k RPM) for a few miles. It make take a longer distance/time if you're in a colder area.
Once the car is at the proper operating temp, then you can start beating on it.

[Demiurge]

This is just a lot of various opinions. I like to warm up, but I have no idea if it's right. Is there any actual data or definitively expert opinion/explanation?

[zaptorque]

consensus: It will be fine if you pull off right after you started up, just don't go flogging it until temps are up to normal operating range.

[Demiurge]

Originally Posted by zaptorque

consensus: It will be fine if you pull off right after you started up, just don't go flogging it until temps are up to normal operating range.

Common wisdom is better than nothing, but this is mechanics, and therefore there is an empirical answer.

[ayau]

Originally Posted by Demiurge

This is just a lot of various opinions. I like to warm up, but I have no idea if it's right. Is there any actual data or definitively expert opinion/explanation?

Concrete data? Probably not. There are too many variables to take into account.

However, there are some things we do know for sure.

Engines need oil to lubricate parts.

Cold oil is thick, and when oil is too thick, engine components aren't fully lubricated.

When components aren't fully lubricated, you have metal on metal contact. This is BAD.

[zaptorque]

Originally Posted by Demiurge

Common wisdom is better than nothing, but this is mechanics, and therefore there is an empirical answer.

Pretty insightful stuff, professor.

[KSC]

Originally Posted by Demiurge

This is just a lot of various opinions. I like to warm up, but I have no idea if it's right. Is there any actual data or definitively expert opinion/explanation?

As ayau pointed out, there is, still, most of this is going to be "works for me" opinions. Someone who brushes their teeth for 4 minutes and never gets a cavity will tell you that 4 minutes is the right amount of time to brush your teeth. Someone else, however, that bruhes for 2 mins with the same results will say that 2 minutes is long enough. Nether will be able to sway the other to change their habits as it worked for them, so why fix it?

Most of us who do it, even if it's placebo, have gotten the desired results from doing it, so we'll most likely continue to do so. Those that don't, don't, and probably won't start now.

[Endless Mike]

Originally Posted by Demiurge

This is just a lot of various opinions. I like to warm up, but I have no idea if it's right. Is there any actual data or definitively expert opinion/explanation?

Volvo manuals have, for years, said that no warm-up period is necessary, just to take it easy until the engine reaches operating temperature. How this applies to other makes is probably arguable, but I would tend to believe that the Swedes know a thing or two about driving in cold weather.

[chenshuo]

i wait for the temp gauge to change just a little bit, usually that's about a minute or so.

[brillo]

I don't wait for the car to warm up to drive but I would never push the car over 4,000rpm until my water temps are ~180f.

[Mr.Corvus]

Originally Posted by chenshuo

i wait for the temp gauge to change just a little bit, usually that's about a minute or so.

Your Fuelly threw me off for a bit, I thought you were getting 7.6 MPG

[Demiurge]

Originally Posted by ayau

Cold oil is thick, and when oil is too thick, engine components aren't fully lubricated.

When components aren't fully lubricated, you have metal on metal contact. This is BAD.

I'm sure cold oil is just less viscous, not 'absent', and there is always some lubrication on the metal surfaces.

I don't think there are too many variables. It's pretty simple, there is temperature range for starter car, there is time to warm up, and there is a way to measure wear. Surely engine makers do this kind of thing all the time, so there must be some concrete data.

[Demiurge]

Originally Posted by Endless Mike

Volvo manuals have, for years, said that no warm-up period is necessary, just to take it easy until the engine reaches operating temperature. How this applies to other makes is probably arguable, but I would tend to believe that the Swedes know a thing or two about driving in cold weather.

Hard to tell from a manual or advice from car company if they're saying it's 'okey' because they don't want me to feel inconvenienced, or because there is actually no difference.

[bcj]

Originally Posted by Demiurge

because there is actually no difference.

This.

Tires have a warm up period too.
So don't rag it out of the gate or you'll be in the ditch opposite your driveway.