SW17LS

That's a perfectly reasonable thing to do, but manufacturers don't describe that procedure as being necessary.

mmarshall

That's not necessarily limited to Toyota products. I've seen that from several manufacturers....it delays automatic-transmission upshifts into certain gears before the engine reaches a certain operating temperature.....usually around 140 degrees, which is the bottom of the normal operating range on the temperature gauge. That, of course, also makes it more difficult to keep the engine RPMs down when cold (the transmission is stuck in lower gears longer).....so even more care has to be taken.

mmarshall

Well, most likely, there's probably a limit to what the Owners' Manual is going to actually print out and tell you. There's a huge amount of stuff crammed into a modern Owners' Manual (indeed, some of them are several hundred pages thick, much of which is insisted by the automaker's lawyers for liability reasons). They aren't going to print even more pages telling you what's obvious.....that you should shut your door before taking off, that you don't drive if you have been drinking, that if you press on the brake pedal, you are going to slow down and stop, or that if you turn the steering wheel left or right, the car will turn in that direction (assuming the front tires have traction). As adults, some things are assumed to be known simply by common sense. However, you are correct in the sense that modern EFI usually precludes the need for long warm-ups and/or idling time like decades ago....though driving with a stone-cold engine, with cold oil, can still cause some friction and drag.

SW17LS

But Mike, the owners manual specifically says this is not necessary. Why would they take the time to tell you that it isn't necessary if the engineers didn't think that not only is it not necessary, but it's better not to do that?

mmarshall

OK, Steve, if you actually saw it in print, then I guess the case is closed. I don't recall seeing it in any manual I've owned, but I'll take your word for it on your car. And, with the very low-viscosity oils that automakers use nowadays, and the advanced packages in them, it probably wouldn't be surprising, since they don't thicken out as much in the cold and start flowing faster. Some engines, though (and the one in my Verano is one of them) will still give you a ticking sound from the lifters and valves after cold winter starts when the oil pressure/temperature is not yet up to snuff.

And.......something many owners may not realize, so I think it needs some clarification.. Once the oil starts flowing and the pressure reaches its maximum after a cold start, which is usually shortly after start-up, unless the oil is really thick (it's easier to watch that on an oil-pressure gauge, of course, than with idiot lights), it's normal for the pressure to DECREASE as the oil further warms up into its normal operating range. That's because, as the oil warms, its viscosity (thickness) decreases, and it flows with less physical force. That's also partly why oil pressure decreases with a low engine speed at idle....it flows at a lower speed, with less force. One warning sign of potential low oil level or pressure is when the red light will momentary blink on and off or be steady at idle, and then go off again as the engine speeds up on takeoff. That's a sure heads-up sign that the oil is either too hot (and too-low pressure at idle RPM) or at too low a level (or both), and it's time to add some.

SW17LS

You're not wrong, your thinking is just 15 years behind he times...

mmarshall

Well, OK, then, in what way? The comments I made about oil viscosity and temperature were correct. That hasn't changed in the last couple of decades...except that factory-recommended viscosities have gotten even thinner (down to 0W-20 in some instances). And some vehicles still do make ticking noises from the lifters when cold.

Toys4RJill

There is no need to warm up your car. The idea is outdated. Most experts actually claim that warning up your car for long periods of time actually reduces the lifespan of the engine. Most will tell you to start the car, then clear the windows and go. Driving the car warms up the car faster.

Radio88

Absolutely correct. I will personally attest to this regarding my 4RX, Which is why I won't start moving 'till the temp needle starts moving from rock bottom to at least the "cold" mark. This is not an unreasonable habit and also is not excessive idling.

Toys4RJill

So how long would you say that you idle for?

SW17LS

Because modern cars and modern oils don't require it. Low viscosity oils maintain their viscosity at colder temps, that's one of the reasons why companies have gone to lower viscosities. Modern engine management systems retard throttle and maintain RPM at a certain level to speed warming and protect the engine at low temps. That's why manufacturers tell you that a warmup period is not necessary.

Technology is ever improving, and when it does certain things we had to do in the past we no longer have to do. Why do you think we don't have to change oil at 3k miles anymore? Because we have better oils and better engines that don't require that.

When's the last time you heard of a car randomly overheating without there being a cause? Used to happen a good bit. Why not now? Better engines, better coolant, better technology.

LexBob2

When you think about the millions and millions of cars on the road, most drivers have their own cold start procedure and millions more don't have any. You don't hear of any widespread issues with how modern vehicles are started hen cold. It seems to confirm the theory that it really doesn't make much difference. Personal preference.

Radio88

Good question as I never actually timed it. So I did you the courtesy of timing my warmup this morning. 2 minutes 30 seconds. This 4RX warms quickly. My 2001 Tacoma needs at least 4 minutes.

Stroock639

in the manual for my 17 year old car it says 10 seconds is all the idle time that is necessary to let it idle before driving off. i usually just start the car in neutral, give it a little push with my foot and let it roll out the garage and down to the road in neutral, and by the time i'm ready to put the car in D it's been about 15-20 seconds which is good enough for me. if it's really cold out i'll let it wait a bit longer, but never more than like 45 seconds.

also another thing to note is that the oil and transmission fluid takes MUCH longer to warm up than the coolant. just because the gauge has reached operating temperature doesn't mean it's 'safe' to start driving it hard. my LS manual says 20 min of driving 55 mph is how long it takes for the transmission to fully warm up, so i'm always very gentle on the first 20 min.

Htony

[QUOTE=SW15LS;9638016]But Mike, the owners manual specifically says this is not necessary. Why would they take the time to tell you that it isn't necessary if the engineers didn't think that not only is it not necessary, but it's better not to do that?[/QUOT
Exception could be extreme cold condition. I only keep cars 5 years at the most. Never had any power train issues caused by my mistakes. When I was working I received
a company car every 3 years. My garage at home is pretty well equipped to work on cars. Have to look after 3 cars and a truck..