Is it necessary to warm up the engine for a cold start?

What's the best way, idling for a few minutes or driving? And if driving, what's the highest RPM to you can go?

Depends on the source. Other sources say only idling and others say it's best to do really careful driving, not passing 2k revs.

To leave it idling for a few minutes is ideal but if you're in a hurry you can simply drive easy till it warms up, even if you do let it idle you should still drive it easy for a bit.

It's not a matter of RPM strictly, it's mostly about throttle - you don't want to go up a hill at 1000rpm in 5th gear chugging away with shitload of throttle either. Just drive in the rev range your engine feels most comfortable nice and easy.

just wait 15 seconds before putting it in gear to make sure oil has cycled through the engine.

Its best to wait for the oil to flow for about 30 seconds then light driving till you warm up

>ae70.jpg
>Clearly a BMW E30 cluster

This.
Also: don't floor it as soon as the temp reads normal operating temperature. Other parts of the motor are still 'finding' their operating temperature. Few more minutes of normal driving allow proper warming up.

Ayy, so no need to sit in idle until the rpm's drop from 1.1k to 700?

If you have the car above freezing, you can idle the car for warmth. You're better off using a remote start and electric heat sources (heated steering wheel [or cover], heated seat) because those will warm up quickly.

If it gets below freezing then idling is really the worst way to warm up the engine, it takes forever. You just want to wait around 30 seconds for the coolant and oil to warm up. Then drive conservatively, avoiding aggressive acceleration, until the engine temperature needle starts to rise up from the C on the gauge.

>warm up coolant
Yes numbnuts, coolant both cools the engine and distributes heat. When the engine is cool, it takes the heat generated by the cylinders firing and pipes it through the heater core. Then air is blown over the heater core and that's how warm air gets into your passenger cabin.

This is also how an engine block heater works, it warms the engine block (often where the coolant is if factory installed) to keep the engine warm. This makes the engine easier to start in colder weather and allows the vehicle to warm up faster than it would in extremely cold weather).

If it gets below zero F (-18C) then don't bother trying to idle the engine for heat in the passenger cabin or for the engine to meaningfully heat up. You can idle that car for thirty minutes (rougher on the engine when it is cold) and it still will be cold. You wait 30 seconds and drive.

No. Just turn it on and then get your a/c and radio set right then drive away. Drive gingerly until at operating temperature.

The moment the revs drop to normal, you can safely go. Drive slowly until the water temp goes up. And you can hoon it couple of minutes after all the fluids and components have reached equilibrium.
You won't ruin an engine by idling it, but it's better for the car to drive slowly than sit in one place.

Mine takes exactly 30 seconds to drop the revs, regardless if it is 35°C or -10°C. I always wait it out because tarbu.

If its a relatively modern car you can turn the car on, wait 20 seconds for the oil to flow around then you can drive off. Make sure not to drive too hard until the engine gets to its operating temperature

To expand on this, reason why letting the engine warm up on idle before driving is a bad idea is because this doesn't warm the gearbox.

Neither is the temp gauge in on your dash the temperature of the engine, but rather the coolant fluid. Realistically it takes around 10-15 min of driving before the engine in total has warmed up completely and is ready to be trashed around. Reason why coolant is metered but oil isn't (usually) is because the entire coolant system works best under certain pressures and require the coolant to expand due to heat before reaching that pressure.

>The moment the revs drop to normal, you can safely go.
>Mine takes exactly 30 seconds to drop the revs, regardless if it is 35°C or -10°C. I always wait it out because tarbu.

Fuck, mine takes 2 minutes for revs to drop to normal (and the thermostat opens shortly afterwards).
t. 130k miles 2005 civic

Ha, I have an oil temp gauge, but no coolant gauge.

Thanks BMW.

I wait 10-15 seconds before pulling out then I don't go above 4000RPM until the needle has made it into the lowest temperature on the oil temp scale.

I let the engine idle for like 30-60 seconds, then warm up the gearbox by putting it in D and waiting for another 30-60 seconds. This warms oil just enough to lubricate the whole engine. Gearbox part is optional, but highly recommended for the shitty one I have in my car.

>turn key
>let engine idle until revs drop to normal idle
>drive off
There is no fucking discussion, this is THE way to cold start any gas vehicle with direct injection

I let it idle for like a minute to get the oil moving and then just drive gently until it's at temperature.

Driving around with revs at most 2.5k. Keep in mind that water will get warmer faster than oil so dont go around hoonin exactly when the water temps goes up.
Driving around warms up the gearbox and diff, while sitting in place and idling doesnt.

>start car
>lights on to warm up shitty bulbs
>get out car and brush off snow and scrape off ice
>slow and easy driving until temp reads mid

I don't have any temperature gauge.
Is my car warmed up? WHO KNOWS?

I just let it idle for 20-30 seconds, then drive it easy for a mile or two.

If its cold as fuck outside Ill warm the bitch up. Otherwise Ill pull out and start

I do pretty much this. In my Audi it's usually around a minute, then I just keep the revs down until I'm at temp. I don't think there's much that can go wrong with this approach.