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View Full Version : Warming Up a Car or Truck. Things to Do and/or Not to Do?


Clough
Feb 1, 2010, 10:11 PM
Hi, All!

I'm wondering if there are things that should and/or shouldn't be done when starting a car or truck in the wintertime.

For instance, I've heard that vehicles with automatic transmissions should simply be driven right away and that those with manual transmissions should sit and be run for a number of minutes before being driven.

Is that true or false?

Does it also make a difference as to the type of fuel that's used to power the car or truck as to whether it should sit and warm up before being driven or not?

I don't know all of the ins and outs concerning those things and would appreciate more information.

Thanks!

KISS
Feb 1, 2010, 11:01 PM
In reality it comes down to having the correct oil pressure and we don't have these gages anymore so runnig the engine at low RPM until you have enough oil pressure.

As you learned before viscosity is dependent on temperature for car oils anyway, so you have to wait a few minutes for the oil to get slightly warm and don't race the engine. The use of an oil pressure gage is the best way of doing this.

The manual transmission is just a case of 80 wt heavy oil. And all of the gears are immersed in this stuff. It's not pumped through passages.

The automatic transmission, I'm not sure if it runs the pump in park. I'm almost positive it runs in neutral. That fluid has a very low viscosity, so pumping it isn't a problem. The transmission fluid is cooled by the radiator of the car and it prefers a cooler temperature.

So, what you want to do is not floor the accelerator in the winter after just starting the car. You should always drive gently until the car reaches operating temperature.

Adequate oil pressure before driving away is he key.

Electric, hybrid, fuel cell, diesel may or may not fit the above model. An all electric car like the Volt doesn't. Most will fit the above model.

Diesels like to operate at a nearly constant speed. Diesels need help getting started with glow plugs. I'm not too familiar with them.