Faster engine warmup
 

During this cold season, I have been turning off the car heater until I see normal operating temperatures from my coolant gauge (approx 4min). My theory is that this slightly reduces the time needed to warm the engine and enter closed-loop mode. Is there any benefit to my practice? If so, any guess as to how much of a benefit could be found?

The idea sprang from what I had learned about an over-heating car I used to drive in high school. Whenever the car would begin to over-heat, I would blast the heat on full to control engine coolant temps. Not fun when it's 100 degrees outside!

...put a 100W lightbulb inside a metal-bulb protector under the oil pan each night.

...just don't forget and run "over" it as you leave or drive back!

Yes, your car will warm up much quicker with the heat fan turned off, but is it safe to drive your car like this? are you getting enough defrost to see out the windows?
Most of the winter I never turn my heater fan past the first or second setting because I can see my temp gauge needle drop if it's cold enough, but it's hard to scrape the ice off the inside of the windshield and drive at the same time so I use the fan for defrost.
When I can I plan to install a block heater so I can start out with a warm engine right from the start, from research and testing done it would appear that for most cars it uses less energy to use a proper block heater to preheat the engine then it does to drive with a cold engine and both of those use way less energy then it takes to idle a cold engine to warm it.

In my 81 if u blast heat in a 30 deg day it can take up to 10 miles to warm up. But off it about 3 miles.
Cut off about 2-3 miles with a grill block. But that is where I am at now.
Oh interesting note before grill block my 81 would cool back off to the c line. If it was under 30 and fully warm. U could suck all the heat out of it and it would soon blow cold. Hasn't done that since block.

So in my experience with every car I have driven yes. I usually turn the dial to cold and hit recir. also trucks take almost twice as far as cars.

The OP's technique is sound, and it becomes more important as your driving gets more efficient. An ecodriver burns less fuel, hence increasing warm-up time. It can take me 15 minutes to warm up with the heater set to "cold", whereas with it set to "hot", it wouldn't happen by the end of my 20 minute commute.

The heater plays a BIG role in my coolant temp. If I want my engine to properly warm up, and get to operating temperature, I can't have the heat past my notch above 'low' (on a scale of "off, low,-,-, high) or my coolant just doesn't heat up. I get angry when I leave my heater on two notched above 'low' when I reach my car warming up (auto-start, mostly turned on a minute at most in advance). This morning is a great example of my heater control methods. My external temp gauge read I think -8F. My engine coolant needle was limp, so I didn't turn the heat on. As I drove down the road, I could see fine, no frost or fog for a while. As the needle was 1/4 towards operating temperature, frost was forming on my windshield. I cranked the defrost up to the 2nd notch after 'low', because safety>MPGs>speed. Once the frost was gone, I turned it down a notch, and put it on the interior vents (my gloves are horrible, and the steering wheel is cold. The vents are pointed towards 2:30 and 9:45 on the wheel for my fingers) and my coolant reached operating temp. On any given morning, once the needle is resting at operating temperature, I crank the heat.

Here is my method for maximizing warm up mileage.

I keep the car in my garage to eliminate window frost issues. On start up I immediately put it in gear and go. Pulse and coast with engine on, and no heat or any other accessories unless they are absolutely necessary.

I start coasting (engine on) before I have travelled .1 mile, and continue until the engine has reached operating temp in about 2.5 miles. By the 4 mile mark I have passed the EPA highway rating for fuel mileage, which on my car is 31 MPG.

I keep a window cracked and air flow through the car. Usually do not use any heat or defrost, and wear extra clothes to keep warm.

Even in temperatures capable of freezing salt water this usually gets me close to 40 MPG by 7 miles from the cold start, at average speeds of 40 MPH.

regards
Mech

My intention is to construct a grill block, but I severely injured my back, so it will probably wait until next cold season. I drive a stick, so that tends to increase my warm-up time since I do not rev my engine as high as an automatic would. Of course I'm not going to do something excessively unsafe, and I do park in the garage to avoid frost. My commute is only 15min, so no temp can chill me in that amount of time.

Block heaters are just more effort than I'm willing to give. The grill block will have to do for now. After that I have no mods planned to improve mileage, except maybe LEDs, which is more for the fun factor and less about mileage.

...the "heater" is just another, albeit littler, radiator that's located inside the passenger compartment, and "wasting" heat-energy.

...of course, when it's COLD outside, the "wasted" heat-energy sure does feel NICE.

Okay, first person to make an exhaust-heated car heating system wins... something. Go!