Page 81 of the 2007 Boxster Owners manual says "Do not idle engine to let it warm"??

[kavlono]

Why should you not let the engine warm by idling it? The manual says you should begin driving right away. Anyone know why this is?

[RandallNeighbour]

Germans are obsessed with conserving fuel and reducing emissions. Allowing the car to warm up, especially when it's snowing outside, seems like a good idea to me to reduce engine wear.

But that's just me, thinking like an American, not a German.

[John Y]

Originally Posted by kavlono

Why should you not let the engine warm by idling it? The manual says you should begin driving right away. Anyone know why this is?

Every owner's manual will say that, because: 1. You are wasting fuel sitting there, more, also, than you would at a warm idle by contrast because the engine is running richer when cold. 2. You are increasing emissions, (a) because again, you are spending extra time with the car running just sitting there, and (b) because the cold motor emits more hydrocarbons than one at operating temp because the cats have to heat up to do their job with max efficiency. 3. You are defeating your own purpose - you do this because you want your engine to be operating at warm temps, which is better for the motor - but all you are doing is PROLONGING the period at which your motor is operating BELOW it's normal operating temp. That is because it warms up MUCH more slowly when just idling than it would by being driven. I'd encourage you to prove that one for yourself, but that would be...well, you know

So, the best thing you can do is drive off basically right away (seatbelt on first of course ) remembering to operate it gently until it's warm - light throttle loads and moderatate rpm until then!

[John Y]

Originally Posted by RandallNeighbour

Germans are obsessed with conserving fuel and reducing emissions. Allowing the car to warm up, especially when it's snowing outside, seems like a good idea to me to reduce engine wear.

But that's just me, thinking like an American, not a German.

You are quite right on point #1, but really not on point #2. Not a cultural issue, just a technical one. And I'm half German - they are pretty anal about the fuel conservation issue, but you don't know the half of it when it comes to the things they will do, not all of them great for the car. But this one (not letting the car idle after you start it) really IS a win-win proposition on both environmental and technical grounds.

[Brucelee]

The car will reach operating temps much more quickly if you simply drive easily after starting.

If it were me, in very cold weather, I would give it a minute to warm up if the car is stone cold.

Of course, we don't have that weather here so I just drive.

[RandallNeighbour]

I will still let my car's engine and transmission warm up in cold weather at idle in my driveway. My 1-2 and 2-1 shifts are impossible when the outside temps are below 50 degrees farenheit.

On a side note, I noticed that the temp gauges in the 07 S's seem to rise to their operating temp very quickly compared to my 10 year old 986. It just seems too fast to be accurate. I'm wondering if they changed the system over to an idiot-light style temp guage (that don't move unless the car has reached an overheating point).

[porsche986spyder]

Most mechanics will tell you that if the car is cold because of the cold weather outside it is okay to let it warm up at idle before you start driving it. Most of us do this to circulate the oil through-out the engine BEFORE you start driving it on a cold day. This way there is more lubrication and less chance of dry gears and pistons grinding together. So in the summer when it's hot and the oil is already at room/outside temperature it probably is safe to drive away without warming up your engine.