optimal warm up time

[curtis265]

Yeah i can't decide whether it's better to sit and let it warm, or jsut go.

on my dad's mazda 6, it gives u crazy fuel consumption numbers if you drive with the cold engine, but when it's warm it's more normal.

Maybe 1-2 minutes warm up is a good idea.

[OMG.JAI xD]

Turn on, make sure you have oil pressue, then go. No need to sit and warm up. Just make sure you drive 'normally' till the car has warmed up completly (10mins or so)

Spot on.

EFI engines dont need warming up.

Though it is better.
Waste a few mL of fuel every cold start up and prolong your engines lifespan a little bit.

Clearances are bigger when its cold, driving off even with granny driving still puts load on the engine. I only warm up on mornings. Other times I let the oil run thru the system and drive off.

I dont like cold engines anyway. Oil pressure doesnt get high enough for vtec to kick in.

[string]

I dont like cold engines anyway. Oil pressure doesnt get high enough for vtec to kick in.

VTEC doesn't kick in because it has an interlock on coolant temperature (for good reason). Oil pressure is highest when your engine is cold...

I see 80+psi about 2seconds after the car has started. Seat belt on and your off.

[migoreng]

just let your car sit for 15secs then drive off slowly..
i see many people that start the car, put then handbrake down and drive within 2 seconds...

i have to open my gate/close the garage every morning so my car gets over a 1min of idling before i start driving

[aaronng]

It takes about 3 minutes for coolant temperature to reach normal temperature and about 8 minutes for oil temperature to reach normal on my car. And if I let it idle from cold, the oil temperature does not reach the operating temperature for a long long long time.

[JohnL]

just let your car sit for 15secs then drive off slowly..

That's fine.

i see many people that start the car, put then handbrake down and drive within 2 seconds...

And that's perfectly OK as well, but you seem to think it isn't?

I suspect you might be concerned about whether oil has circulated to all the nooks and crannies of the engine in the first few seconds, but really as soon as the oil pressure light goes out it's fine to raise the rpm a bit and put some light load on the engine.

It's actually a good thing to (within reason) raise the rpm very shortly after the OP light has gone out in order to quickly spray some oil up onto the cylinder walls (which will be relatively dry at start up). This is a good thing that the 'cold fast idle' does, but a bad thing is that it tends to not wait for the OP to build up...

i have to open my gate/close the garage every morning so my car gets over a 1min of idling before i start driving

Not ideal IMO, but then the 'cold fast idle' speed is probably high enough to spray an adequate quantity of oil around...

[JohnL]

It takes about 3 minutes for coolant temperature to reach normal temperature and about 8 minutes for oil temperature to reach normal on my car.

Exactly. Which is why coolant temp alone is not a good indicator of the engine's readiness to be thrashed...

And if I let it idle from cold, the oil temperature does not reach the operating temperature for a long long long time.

So if the engine is idled up to temp then when that point is reached, the coolant will be 'hot', the engine oil only warm, and the gearbox oil for all intents and purposes dead cold...

[UCNDRM]

I actually had the same question regarding my car and the dealer actually told me to warm up the car for bout 2 mins and cycle through the gears up and down a couple times to get the fluids moving on cold starts, it is supposed to help out with the cold morning notchiness

[aaronng]

I actually had the same question regarding my car and the dealer actually told me to warm up the car for bout 2 mins and cycle through the gears up and down a couple times to get the fluids moving on cold starts, it is supposed to help out with the cold morning notchiness

If your car is an auto, you don't need to do that. "D" lets it go through all gears with no restriction.

[curtis265]

yeah i hate gold gearboxes. 1-2 doesn't go in properly, andi have to double clutch to get it in

[trism]

ive posted thisd a few times

warming a car up is the worse thing you can do, for a few reasons, if you have a search youll find them all, but here is a quick run down

1. idling causes fuel wash. the excess fuel in the cylinder not being burnt literally washes the oil off the cylinder walls, removing lubrication
2. emissions control devices, specifically the catalytic convertor work when heated up. idling the car isnt going to heat it up, so for the 5 minutes its warming up all the toxic nastys are spewing out the exhaust.
3. youre wasting fuel warming up. the ecu automatically supplies more fuel when cold to prevent stalling. thus wasting petrol (and causing fuel wash)
4. you sit there for 5 mins warming the engine up thinking youre sweet, then pull out and give it a hit thinking its all fine. well its not. where does the power go through before it hits the wheels? the gearbox/rest of the drivetrain. you hit it, and your 'box is cold still and you cause wear on the drivetrain.


thats a basic run down on why its not necessary. simply get in, start the car up and drive away, taking it easy until the temp reaches operating temperature, that way everything warms up at the same time and you dont damage anything

[UCNDRM]

If your car is an auto, you don't need to do that. "D" lets it go through all gears with no restriction.

Nah buddy is a manual, 1st and 2nd gear tend to be a bit notchy on cold mornings, hence why i cycle through gears in neutral to get some fluids moving. It just helps with the gear box getting sticky