i try to wait till the rpm drop to 1000 but dont have the patience all the time... sometimes 20sec till 1200...depends if im busy or not.

 

"......manual says not to let the car warm up" - Does it really say that? Hey, I'm a guy! I don't read the freakin manual!

 

I see where you're coming from, but its a bit of a misunderstanding. Your oil has to reach a certain temp. too, not just the water temp displayed on the gauge. Since it takes a few seconds to cycle, starting and going isn't an issue.

A proper break-in goes a long ways towards extending engine life by sealing the motor properly, and this will be the primary means for engine longevity. As for sudden rise or drop in temp, the engine is firstly built within tolerance, while driving easy below 3Kish rpm certainly does not cause a dramatic or rapid enough increase in temp. for most fuel injected engines* to see any problem, especially when considering a proper break-in. Just keep the RPM/speed low, avoid torque spikes/engine load, and generally take it easy.

Yes you let a car warm up before getting on it or doing emissions, but warming up is the process of driving it easy- not necessarily idling to operational temp or for more than a few seconds (which is again, all that the oil requires). Idling inefficiently burns gas (which is worse for the engine), takes the longest time to warm, doesn't allow all parts to warm together, and puts out the most emissions. While these are the tradeoff, idling won't protect your car any better than just driving easy, which avoids all of these issues.


*[Lexus V6] The dual injection system also reduces cold-start emissions. The port injection system dumps a bit of fuel on the back of the closed intake valve; when that valve opens, the fuel is evenly distributed throughout the cylinder. As the piston approaches the top of its travel, the direct system injects a bit more fuel into the cavity on top of the piston. The total air/fuel mixture in the combustion chamber is slightly lean, but the mixture is significantly richer in the area around the spark plug, making it easier to ignite in a cold engine. The result is quicker warm-up and smoother operation when cold.

 

Of course emissions are much worse when the car is cold. The catalytic converter hasn't lit off, and the mixture is extremely rich. But why do you think it is "safer" to let the car stay in this state for a longer period of time than necessary by idling?

I go by what the engine manufacturer recommends, and drive off soon after starting the car. (I picked the 20 second choice on the poll, since I put my seat belt on, fire up the iPod, etc. before putting the car in gear). In order to protect the engine, I don't "get on it" until the car warms up. (My Audi had an oil temperature gauge, which was much better for determining when it was safe to 'play' than the water temp gauge on the Lexus).

 

I wait until I have to press the "I Agree" button on the Nav Screen, which I think is about 5-10 seconds, just to let the oil begin circulating in the engine. Then, I drive very moderately for 10-15 minutes before I rev it past 2.5K. I noticed that this engine has a very fast cold idle speed, > 1,200 RPMs. And, it takes a bit of driving for it to settle into its normal idle speed.

 

I would love to see some info behind this statement. I think it is totally backwards.

I agree with lobuxracer. Idling is bad for a car. I'm not saying you should run it hard when cold, but I try to idle as little as possible. There are many reasons, but the biggest in my book is that the piston rings don't seal well under vacuum (no throttle), so the oil gets contaminated by blow-by (fuel, moisture, dirt, etc.). It takes a pretty long driving cycle to burn those contaminates back off again. If you do a lot of short commutes (< 20 minutes), and do extended idling, your oil will be contaminated quickly. That's a big reason why highway mileage is better than city mileage.

 

BTW, I also have a feeling that emmissions are better if you warm it up while driving instead of idling. It's going to take LESS burned fuel to warm up the cats under load than it will at idle.

 

With a new stock Lexus engine, you just need to start and go. If u idle, your just causing pollution and hurting gas mileage

 

This is what I thought as well and what I have done to my previous 15 cars.
Is it only for the new IS?

 

No, this statement fails to account for modern metallurgy or engine design. There is tremendous thermal change with every single piston stroke. A few hundred times happens in seconds. No, it's not going to crack anytime soon.

Start the engine. By the time you've pressed I accept on the nav, you are ready to drive and should do so. Any further sitting and idling is more harmful than good for an engine.

NOTE: Extended idling is specifically identified as a key factor in applying severe duty maintenance schedules. It is BAD for service life.

 

How about in cold climates when it’s -20C (-4 Fahrenheit). Should I let my car iddle for 5 minutes or just take off and keep it below 3000rpm? Lets say I didn’t plug in the block heater. Actually I’m not even sure I have one, must check.

 

If you're running a synthetic oil, no you don't need to, and no it's not good for the engine. At -30C I'd give it 30 seconds, then drive away - just enough time to be sure the oil got to the top end. Engines always warm better under light load. But if I lived where I expected those temperatures regularly, I'd be checking on that block heater for sure.

 

If I'm going to be late for class: 15 seconds.

If I'm almost late for class: 25 seconds.

If I'm feeling like ditching my PHY132 class in the morning: I'll mope around and wipe the car for a good few minutes lol.

 

No, it's a common misconception from the days of older carburated vehicles. Warming up for me in any modern car, is driving easy under light loads, which takes between 3-4 miles to fully warm-- the engine doesn't suffer from any added stress, and it causes no problems at all.

What about a cue for those without nav?

 

i keep my truck in the garage year round. When i start i pull out and stop right after the engine is started. If i forgot something i run in and grab it, if not i just drive off. Once i get up to temp and feel like all the fluids are good...i begin to "drive".

in the winter i baby it until i dont see any more vapor coming out of my exhaust through my rear camera. Then i get on it a little till ive been going for 5-10mins...then i let er rip!