Block Heaters Effect on MPG

[bronsin]

Well I bought my first tank of gas after installing and using the BH. 33.9 mpg which is pretty close to what I get in summer.

That is driving 6.7 miles to and from work almost exclusively.

BUT...

Average overnight temps have been in the 30s. Sometimes high 30s. Sometimes in the 40s. Its been ususually warm so far. Last winter 15 degrees every night!

The Cool Engine Light seems to go out after .5 mile with the heater on for 2 hours.

Without the BH about a mile.

I dont use the heat at all because I did it once when using the BH and the CEL didnt go out for more than a mile. Thats with the heat on full red and the fan on 4.

The experiment continues...

[bronsin]

Second tank of gas...and the mileage was...32.66 mpg.

I should note that I made half a dozen short trips to the store >4 miles each which I normally do not make.

Not good for mpgs.

Drove to work this am without the benefit of the bh. Cool engine light went out after 1 mile. Temperature nearly 40 degrees.

[nemelek]

Garage my car. A block heat might help some. The idle time it takes to scrape windows and remove snow is still there. I do have Dodge diesel with a block heater. Without using it, the truck takes over 10 miles to heat up.

[bronsin]

Diesels are notorious for taking a long time to heat up.

On th other hand because they have significantly higher combustion temperatures, you do NOT want the overheat warning light to come on. That usually resluts in a blown head gasket. Ive seen pistons melted too.

I scrape the ice THEN start the engine. No burning gas unless the car is MOVING.

[Aiko Cargo]

^^ This. Cars warm up faster when moving.

[Idahotom]

Anyone using an inline type of coolant heater in the lower radiator hose? I already have the upper block heater, and was thinking a lower radiator hose heater would give faster and more complete warmups. They are cheap and easy to install FWIW.

[bronsin]

I was thinking that too. Plus they typically are twice the 400 watts of the Toyota one.

[Idahotom]

Well, I put one in last night. As mentioned I already had the Toyota one, I'll check the wattage of that and the in line one I just installed (using a KillaWatt meter). My main incentive is the long downhill run I have leaving my place, and even with the top grill blocked and the bottom half blocked the temps plummet so no cabin heat for the first ten minutes or so! I don't want to keep everything plugged in all the time, (the easiest way of course) but do want increased results with short plug in times.

A drawback of having a super effcient small engine, not a lot of extra waste heat!

[bronsin]

Our electric rate is 12 per kilowatt hours so 2 hours of plug in time for the Toyota heater is >12 cents. (400 watts).

Im using a 700 watt hot plate under my motorcycles (ST1300) oil sump for 2 hours also. That engine takes 3+ mile to reach 3 bars on the temp gauge (normal running temp) without heat and 2 miles with heat. That bike has a mile o meter which I do not believe. Hopefully a mile more with full heat on a 6.5 mile trip will make a difference.

[Idahotom]

I checked, and with everything plugged in I'm drawing 1115 watts: 605 for the new rad hose heater, 410 for the Yaris block heater, and the oil pan heater.

I think an hours plug in time will be pretty effective, (I keep it in a unheated garage)and only cost me 7 cents at our rates. Thus better for somewhat spur of the moment trips.

[bronsin]

Do you have a timer?

[Idahotom]

No timer, and I go to work at different times, never knowing when. So, I figure having a hot rod pre heat system is the way to go for me.

[bronsin]

Yup. You want watts to the max.

[fnkngrv]

this is an interesting thread...I have been curious about having a hose heater or block heater myself. The timer idea seems like a great one. Traditionally most folks I know plug them in at night and then when they leave in the morning of course they unplug. So effectively the heaters are working for 8-12 hrs per night and then some of them will plug in all day while in the office to boot.

[bronsin]

Originally Posted by fnkngrv

this is an interesting thread...I have been curious about having a hose heater or block heater myself. The timer idea seems like a great one. Traditionally most folks I know plug them in at night and then when they leave in the morning of course they unplug. So effectively the heaters are working for 8-12 hrs per night and then some of them will plug in all day while in the office to boot.

12 hours of heating time would be a total waste and probably counterproductive.

Unless you could do it at work in which case nothing could be better.

What I am trying to do is mimic the thermos flask of the Prius which keeps the coolant hot so as to hasten warmup and so improve mpgs.

Which could be a total farce. They say the "engine cut off at stop and then restart when ready to go" feature does little or nothing to help mpg.

I know the Prius to be a total fraud but for some inexplicable reason want to try out the "features".

[Still Learning]

I used to have an F-250 diesel truck. I plugged it in nightly in the cold weather to help with starting in the morning. I put a timer on the plug and set it to turn on 2 hours before I left for work. The engine oil was just warm enough for the truck to start easily. And I didn't use 8 hours of electricity either.