Engine Warmup?

I suggest you ask your 5-minute buddy to provide an explanation of why he is doing that. Let's see what he comes up with.

Modern engines do not need to be 'warmed up' before driving. That's what fuel injection, engine management computers, heated oxygen sensors, etc are for. Unless you are preparing for a race and need maximum power from the get-go, it makes no sense to burn $4/gas while going nowhere, not even for your 30 seconds. A cold engine also wears more and pollutes much more than a warm one, so the fastest you get it to operating temperature, the better. And the way to do it is to start moving. Just my humble opinion, of course.

You make 40-60 degree F sound like it's cold.... This is "shirt-sleeve" weather, my good man....

Start it up... give it a few seconds for the manufacturers recommended oil viscosity grade to circulate and start driving it. Gently at first, allowing yourself to get a little more agressive as the engine warms.

FWIW... starting the engine and allowing it to reach operating temp is still going to leave the transmission and other driveline components cold. There is nothing to be gained from this other than a "warm face".

First I turn on the ignition and let it set until it stops beeping. Then I start it up and let my car idle until the idle speed drops to normal which takes about 10-15 seconds usually.

I don't know if it's true or not but I've heard that when you first turn on the ignition ('91 Explorer) the computer is checking all the sensors and deciding how much air/fuel and all to give it depending upon how cold it is and all.. In any case it probably can't hurt to wait 7 or 8 seconds before starting it.

I also don't change direction while moving. If I back up I wait until the car is completely stopped before shifting into D. Again, I don't know if this really does any good...

Yes. Reversing direction on the drive train (vs bringing it to a stop then changing direction) will definitely wear it out faster.

David

It's just like turning on a computer... there is a POST (power on self test) that occurs... The PCM checks sensors for baseline readings (paying particular attention to barometric pressure, intake air temp and either engine coolant temp or engine oil temp- comparing these to "look up" tables to determine starting strategy) and may "sweep" some or all of the PCM controlled actuators. Well known is that the fuel pump runs briefly to bring the fuel rail to pressure, but the PCM may cycle other actuators that are monitored to determine circuit integrity.

Even with the baud rates we had in the early 90s, there isn't really any need to wait more than a second or two to ensure that the POST completes.

If you have the chance, open the hood and have an assistant turn the key to the run position... you are sure to here at least a few little clicks and clacks as the PCM performs it's duties.

And people wonder why gas is $4 a gallon.