how long should i warm up my 1992 cadillac brougham in winter time?

many professionals would argue that the effects of warming the engine cause just as much wear on the engine as getting in it and going. I would recommend that that you warm i for no more than five minutes unless it is unbearably cold. also due to the colder temperatures Chicago experiences in winter I would recommend 5w-30 because that will allow for more oil flow at lower temperature. Make sure to switch back before summer though. My mom drives a new 08 escape that uses 5w-20 all year so you should be fine to use the 5w-30 up until late spring or temps go about 75. hope I could be of some help Happy Holidays!!!

We are warming the engine to make the oil circulate in the engine blocks.Five or ten minutes is fine and when you start driving the car,the engine will continue warming it.

I don't have an answer to your question, but I'd just like to say that you have one of the most underrated american cars ever made. congrats.

id allow at least 3-5 minutes before i took off in it,this way all the liquids and oil gets a good chance to warm up and start circulating real good,and its a lot easier on an automatic transmission to let it warm up rather than to jump in it cold and take off,it will eventually cause damage to one,also you don't get in to a cold vehicle by letting it warm up you also get the heater going good,good luck.

A well running and tuned car should not really need to run very long at all. Just a minute or two in very cold temperatures to get the oil running, but engines don't take long to warm up. If it is extreme, then maybe a couple extra so the oil isn't thick, but it shouldn't need 15 minutes. Not only is it bad for the environment, but makes you an easy target for car thieves (Unless you are going to sit there in it while you are warming it up...)

I just wait long enough to get the defrost going so I can see, then let the car interior heat up as I drive.