Engine Temperature

[cprogrammer]

Hi,
I don't understand a few things about engine temperature. Why is it bad to not let the car warmup? Sounds like an unusual question, but the engine is not human its a machine so why does it work better at warmer temperatures. And shouldn't it work better at colder temperatures, that's why they have Cold Air Intakes, since the cold air makes the engine work better?


Sorry for the unusual questions, I don't understand it.


Thanks.

 

[Pink_Floyd]

Hmm, well actually you shouldn't let the car warm up. The best thing to do is start the car and drive right away. However, you should avoid going above 3,500 RPMs and take the corners easy. Also leave you heat off until the engine has reaced optimal temperature. You want to make sure you are driving around to warm up your car because not only is a cold idle warm up bad for the engine, it also doesn't give a chance for all the other components of the car to warm up - most importantly being the differential, transmission and all the suspension components.

It is important that the engine is at it's optimal temperature. Though the engine is not human metal does still expand and contract. The parts will work together with less wear and tear once they are at the correct temperature; also, metal parts are more easly broken when they are cold and the oil is not as effective until it is totally warmed up.

The engine should not run best cold. Coild air is better for an engine because it is more dense than warm air and hence has more explosive power. Cold air makes the engine work better, but the engine will only work it's best at optimal temperature.

 

[Big Daddy]

Good answers Pink_Floyd and very true!

 

[cprogrammer]

Thanks Pink_Floyd! Great explanation I appreciate it.

 

[Kirby]

Good description Pink. The BMW Manual also says this:

Starting the engine
Do not allow the engine to warm
up by leaving it running while the
vehicle remains stationary. Instead,
drive off immediately at a moderate
engine speed.

Trivia: I was told that remote car starters are illegal in Germany - it is against the law to let a car sit at idle to warm up, presumably due to pollution and wasting fuel.