Excellent points.

My experience with using jumper cables is that the car providing the jump is much more effective if its being revved up -- way up (and burning the precious fuel at a higher rate).

In cold temps it would take my car a few minutes to get the heater really hot. In a gridlock situation like we had yesterday I'd much rather rely on my clothes, sleeping bag and chemical warmers (for feet and hands).

In my experience, the temperature in a vehicle seems to drop very quickly as soon as you turn off the heater. If I was stuck, I'd probably just shut 'er down, bundle up, and wait.

No idea if this has been posted yet sorry if it has.

http://www.youtube.com/watch?v=OPABQW9gN2Q

Perhaps you did not close all the vents, so the hot air just escaped? Also it's a typical mistake (at least here in California) when people are trying to use car heater or cooler leaving the main ventilation switch on intake (instead of recirculating)... And of course the heat retention depends on a particular vehicle design.

My own experience is that each person inside the car heats it about 15 degrees. With two people inside the car, you'll take a long time before you stop producing enough heat.

Then recommended 10 minutes doesn't have to be in one block.

I do a lot of waiting in winter, so I turn the heat up high, the blowers on high, and leave them there. I heat up the car until it's really warm, then turn it off. I don't run it for 10 minutes and then suffer for 45.

Cars just aren't insulated very well, and you don't see many double-paned car windows. I carry several cheap mylar blankets, and if necessary, I would roll the edges up in the windows and drape them down the car doors. This would probably work even better with several people on board.

Sue

You're right, it doesn't have to be 10 consecutive minutes, although I assume that's how the procedure is understood by most folks who hear it on the TV or radio.

From what you're saying, Sue, it sounds like the 10 consecutive minutes/hour way doesn't work all that well and that more frequent episodes running the engine would be better. However, I wonder if the battery issue would be even more an issue if I'm doing multiple engine start/hour for 10+ hours. However, maybe idling at higher RPM's to increase output from the alternator (and get more heat, to boot) may compensate. I just don't know, which is why I'm wondering what people's actual experiences are who have tried it.

Arney, I'm not sure I understand what you mean by "the battery issue". Mechanics and electricity are beyond my understanding.

I'm thinking you mean that repeated starts several times per hour for 10 hours or so would damage the battery. If it lasts the 10 hours and gets you home, pay $100 and get a new battery. How much would most people be willing to pay to avoid 10 miserable hours in a cold vehicle? Maybe $100?

Like one of my crews said when we passed several cars parked alongside the freeway with their lights flashing very early one Saturday morning (I'll guess the drivers were arrested for DUIs). One said, "Their batteries are going to be dead by the time they make bail". And the other one said, "A $100 battery is cheaper than having that new black Mercedes get hit in the dark and totaled."

Freeze all night and save the battery... *shrug* I would say that is like dying of dehydration in the desert with a canteen still half full of water because you were adamant about rationing it for tomorrow.

Alternate idea: invite other stranded people into your car and the combined body heat may keep you all warm. Of course, then you've got to make other decisions: cute mommy with three screaming kids , or three plain-jane librarians discussing the advantages of the Dewey Decimal system for 10 hours.

Decisions, decisions...

Sue

Drain the battery, can't start the engine, still stuck, no more heater (for the typical, unprepared motorist). I doubt any motorist stuck on the Beltway without heat would die of exposure, but still, it's conceivable for people to be stuck a long time, and you might not be stuck with other motorists to help you. If you may be stuck for a while, it would be good to have some idea how well the recommended advice from the TV/radio works, including how long your battery can last doing that, if in fact you are draining it over time.

The James Kim incident might be an example of a situation where that kind of information helps a stuck, unprepared motorist stretch out how long they have some heat, given their fuel supply and battery charge.

Actually, the emergency flashers is a good point. Way back in high school, I remember draining my dad's car battery just sitting outside a girl's house chatting with her with just the emergency flashers on and the radio on for quite a while. I was shocked, maybe the battery was near the end of its life. Her father was not happy to have to jump start my car in the wee hours of the night. And that was a summer night. I imagine a car battery in the dead of winter would be a lot weaker.

sounds like the making of a good experiment...anyone up north with an ammeter/voltmeter equipped car to determine how long it takes for the voltage regulator to click off from the high charge rate? related would be how long it takes warmed motor oil to reach a viscosity that produces undue drag on the starter motor... good public information service spot for a local news agency... I'm still wearing shorts..