Warming up the car

My husband insists that we not turn the heat on in the car until the temperature gauge begins to register warm. I’m OK with leaving the fan off, but he also insists on turning the temperature gauge to COLD. This results in cold air blowing on my feet. He says the engine will heat up quicker this way. Like I said, I can live with the fan off until the engine heats up, but why turn the thermostat to COLD? I prefer to leave the thermostat on hot until I feel some heat coming out, then turning on the fan. He says we’ll have heat quicker his way. I say so what, at least I won’t have cold air blowing on my feet. As long as there’s no damage to the engine, what difference does it make?

Regardless of any perceived minute advantage of this strategy…it’s not worth it and I say, wait inside till the car is warm or until your husband smartened up as the cold air blew over him alone, which ever came first.

In essence your engine will warm up faster without sending extra coolant to the heater core that will displace heat. Open up a new can of worms and suggest you let the car warm up in the driveway for 15 minutes with the heat off and then go out crank the heat and go, (devil’s advocate here). A block heater at 15 or below is my preference to prevent startup engine wear.

Makes no difference. The engine is computer controlled and when the temp is right it adjusts the fuel mix. Basically the amount of heat you remove from the engine versus the amount of heat made by generating 120 hp is not significant. At 120 hp the engine is producing 100,000 watts plus of heat energy your heater core can extract about 7000w at most. Warming up the car is a waste of fuel anyway.

Will you husband submitt to a test? Try it both ways and see if it warms up faster. I am sure your husband will adjust his behavior when he sees no difference, he sounds like a reasonable guy :).

I can’t put your method in perspective either,you say you want a cold cars heater control to be on hot so you don’t have cold air blowing on you, OK, but a cold car will blow cold even if the heater control is on hot, you must be talking about the transition period when the air is gradualy getting hotter.

I went round and round with one of these “jack of all but master of nothing” mechanics at Christmas dinner. The old demented imbicile insisted that aerodynamics had nothing to do with gas mileage, you can’t fix stupid.

I have to assume you are not married. Being right is not necessarily right.

Heres a compromise. Let the engine run maybe 2 to 3 minuites with the temp control in neutral and let the engine just run. When the temp gauge moves to the first line put the car in drive and go. Then put your heater on when you get on the road becuase it will be hot by then and then drive the car conservatively until it gets warmed up and drive as normal. It’s been woriking for me all the years i’ve been driving and one last thought: If you put the heat on when the engine is cold, wheres the heat coming from?

If there is a difference in warming the motor up with the temp knob on full cold or full hot that difference is very small. The critical factor in warming up the motor is the thermostat. It stays closed to keep coolant away from the radiator. The coolant flowing to the heater core will not take too much heat off the motor block if the fan isn’t circulating the air.

Now, if you live in Alaska and we are talking about temps in the -20 range then I might do the same technique as your husband. Since I’m assuming we are talking about temps in the teens and 20’s as we experience in the lower 48 I’m with you and just don’t run the fan until I see some movement of the temp guage.

I’ve noticed my engine does reach operating temp a bit quicker if I have it on cold in my Civic. If you’re going on a 10+ mile trip, it shouldn’t really matter, but if you’re only going a mile or two, then it makes more sense.

Perhaps I need to restate my concern. I don’t care how long it takes to get warm air through the heater, I just don’t want COLD air blowing on my feet in the meantime. Isn’t there some way to prevent that? It doesn’t happen in my car, but the Chevy Tahoe truck really does blow cold air on you, even when the heater fan is off.

Some cars and trucks, and likely your Tahoe, does run the blower motor at a very low speed even when the dashboard switch is all the way off. Perhaps your heater controls have an “off” position, if so try that. If you still get cool air, then you can redirect the air to the top vent or defrost settings which means cold air in your face but not on your feet.

Hence the suggestion you let him warm his truck up for you…

In the cars that I have owned/own, vehicle speed (or something!) will drive air through the vents with the fan turned off. What I do is turn the recirculation control on which stops the air from coming in and blowing on my feet when the fan is off. I do leave the temperature control on “hot”, though.

Just remember to turn the recirc. back to “vent” mode if the windshield needs de-fogged. Also, in some vehicles you need to have the fan on before the recirc/vent flap will move, so you might have to turn the fan on for a few seconds to do this.

Does 3 times count?

Thanks, sensible advice. We’re also going to check out the thermostat. It just seems to take forever to send out any warm air into the cab of the truck.

…I just don’t want COLD air blowing on my feet in the meantime.

Proper winter shoes or boots will keep the cold air from hitting your feet.