Mini experiments: 300w vs. 800w block heater warm up time

[MetroMPG]

I think it's relatively safe to say that for an engine of approximately this size/mass.

I think a significantly larger engine would have a different warm-up profile.

Anyone?

[dcb]

Just some quick figuring based on standard energy conversion factors

If you run your 800 watt block heater smartly for an hour in the morning, that would be 0.022 gallons equivalent. If you are lazy and plug it in when you get home and run it for 10+ hours that would be a quarter of a gallon and a lot of electricity doing nothing for 9 hours.

edit: it *should* take more time (and energy) to warm up a larger engine. This is based on a motorcycle sized metro engine.

[MazdaMatt]

.022 gal to get near to operating temps... Any estimates on the fuel used to idle up to temp, or the fuel wasted by not being up to temp while beginning your drive? It seems moot to me.

is 0.022 gal equiv based on dollars, or energy conversion?

[mtgeekman]

I just installed a soft plug block heater in my insight yesterday and used it last night for the first time. It uses 400 watts according to my kill-a-watt

I plug it in in the evening, but that is on a timer which turns on at about 6am and off at 8:30 or so. that gives me time on days where I'm a bit late or a bit early.

I don't have a thermometer at my house right now so ambient temps are from weather undergrounds history data.

At 6am it was approx 38f, I unplugged and started the car at 8am. The Scangauge said 112f and didn't drop.

I will change the start time to 7am tonight and see what its at tomorrow morning.

[canhonkey]

Originally Posted by Frank Lee

I like your tests.

Is it safe to say that, as a general rule, heaters should be plugged in from 45 min to 1 1/2 hours, regardless of ambient temp, no more and no less?

This general rule may work for most places, but not some the coldest of places on earth..like Winnipeg! I lived there for a year and a half and would leave the block heater plugged in alllll night and some mornings the Integra would still chug and scrape as it turned over. (it would send chills up my spine..along with the wind) Mind you, it was -40C or below when this happened..yea below..but out there I had my timer set for 4 hrs + before I had to drive it to work. Eventually, I just left it plugged in all the time, especially in January & February.

Those winters are so hard on cars, hard on all the rubbers, hard on everything. Thankfully I'm in Ontario now!

Very interesting read btw,

Ken

[Frank Lee]

I'm not all that far from Winnipeg...

[The Atomic Ass]

Originally Posted by MetroMPG

Another point I often bring up: I don't use the block heater only for reasons of fuel / wear reduction. I really like being warm sooner.

Since I ride my bike in the winter as much as possible, I have some of this: Gerbing's Heated Clothing, and I find it much more enjoyable for use in a car than waiting for the heat to come up in a car. (My parents fleet has no block heaters).

My jacket liner consumes 77w at full tilt, (which I can't operate at full tilt until it's in the teens or below, ON THE BIKE with windchill), and the gloves 22w, though they seem more susceptible to the windchill. I can't operate them at full blast inside a car, either.

My kit probably cost as much as your Forkenswift, but if you can find the stuff used, (it does last a long time), you might find it preferable...

[MetroMPG]

I've heard about the cars left plugged in 24/7, as well as the ones left idling constantly, and the oil/batteries brought in the house at night!

I'd love to see someone repeat this test @ -40c.

Atomic: I prefer a hot engine AND warm air from the heater, and the coolant heater gets me both :P. But there are times I've been sailing where I would like 100w worth of heat in my clothes!

[Bearleener]

The best block heater I heard of was for the Ural, a Soviet military truck. Legend has it that on really cold days you could just build a fire under the engine to warm it up.

Has anybody tried a Thermos-style coolant storage arrangement ala Prius? I tried it a few years ago, but the Thermos only had about 1.5 litres capacity and the hoses were poorly insulated, so it barely worked. But I'm up for trying it again.

[Ecodriver]

Any idea where to buy one of these inline circulating tank heaters for a 1990 Geo Metro? 5-speed 1.0l if it matters. thanks.