engine block heater

It also depends on the length of your commute.

I installed one late this winter/early this spring. All winter in the 20-30F range, I'd get 20-25 mpg for the first two 5 minute bars on the MFD. After that, I'd usually get a 40 mpg bar, and then settle in at around 50 mpg for the rest of each trip.

After installing the heater, I started getting a 40 mpg bar, followed by steady 50 mpg bars. So for me, the difference was 15-20 mpg during the first 10 minutes of each commute.

So: if you have a 10 minute commute, the change will be HUGE. If you have a longer commute, only the first 10 minutes will improve and they're a smaller part of your overall driving, so the overall improvement will be less.

My commute is about 35 minutes one way, so the improvement covered about 1/3 of my morning commute (no plug in the lot at work, so no help on the reverse leg). Looking at my mileage log, it looks like I got an overall improvement of about 5-6 mpg after installing the block heater.

 

I get no discernible benefit from it, other than to say I'm in the club and I seemed to install it quicker than most.

However, don't be discouraged by my gain of 1 or 2 mpg if that in the morning. The beginning of my commute when this would come into play is all uphill. So my issue isn't that the engine isn't warm enough it that the ICE has to work the whole time going up the hill.

As everything on commutes is cyclical, I benefit greatly on the way home from this stretch of hill getting a nice 75-100 mpg bar consistently with 2 to 3 cars.

So, if the beginning of your commute is like mine, it may not be worth it.

steve in grafton Ma
08 Mag Grey

 

I've been looking at an EBH and have a question. How much juice do these pull? I'm wondering if one couldn't be designed to run off the traction B instead of being plugged in.... How long does it take to heat up the engine with one?
On another note, is it true that the whole issue w/ not going to stage 3/4 is that the catylitic converter needs to be heated up? If this is really the case, why isn't there a thermocouple and heating blanket on the cat. conv.?? Seems like it would be easier to heat, and you wouldn't have to run the whole engine....

 

The benefits of the EBH lies primarly in one place: Allowing you the possibility of reaching stage 4 before you exit your neighborhood...

For me, I get screwed on my way home from work, as I'm stuck on the highway, usually in that 25mph zone where I can't turn off the ICE... (needs to get an EV button)

 

The block heater is a 400 W device. Kind of wimpy compared to others.

I have one and don't get any benefit from it. I don't bother to plug it in, as I can't predict when I'll be driving.

And just a comment that made me chuckle, when I purchased Pearl new last May. I asked the salesman if it had a block heater. "Of course!" was his reply. Alberta, Canada!

 

400 W.

My data indicates:
hh:mm - % - dT
0:30 - 49% - 17C
1:00 - 67% - 23C
2:00 - 84% - 29C
3:00 - 91% - 32C
. . .
8:00 - 99% - 35C

The converter is at several hundred degrees and in some conditions, glow a dull red. We're talkin' some serious heat.

Bob Wilson

ps. Here is some operational data taken on a 0C (freezing) morning:

The upper, dark blue line is the engine coolant temperature and you'll notice that once it starts, the coolant from other parts of the engine cause the temperature to dip down a bit and it soon recovers. The interesting line is the orange one at the bottom, the air flow (aka., gas burning.) As the coolant temperature rises the amount of gas burns falls off until about 70C on the coolant line. Thereafter, the engine can auto-stop and save a bunch of fuel . . . we're in "hybrid mode."

The "MG2 rpm" line is directly proportional to the vehicle speed. So while the engine is warming up, I'll get up to neighborhood speeds, ~25 mph, and slip the car into "N" for the most fuel efficient idle. But once the car is in "hybrid mode", other than coasting to a stop light, I pretty much hold constant speeds. That flat plateau between seconds 900 and 1,200 is at 55 mph.

 

Like Poffy74, the first 4 miles of my 24 mile commute is a pretty steep uphill grade. So I plan to install the EBH to get the engine up to temperature fast in order to minimize engine wear when it's 10 degrees F outside and I have to drive almost immediately on a long steep uphill grade.

I think this is a good reason to install the EBH. Am I wrong?

 

Yup, thats a good enough reason.

 

bwilson, About putting it in N when you're idling. Isn't that less efficient since you can't charge the battery in N? Since the ICE is firing to warm itself up while coasting and stopped, you're "co-generating" electrical power and using the waste heat to warm the engine, converter, etc. Taking electrical + heat together that has to be very efficient as your losses are mainly friction and electrical losses.

 

The problem is when the engine is cold, the engine is terribly inefficient with any sort of load. Putting it in "N" during warmup, minimizes the inefficient fuel burn.

It has to do with the engine management systems. If you'll look on the earlier chart between seconds 0 and 720, you'll notice that the lower orange markers continue to decrease as the engine warms up. This is the warm-up inefficiency that we want to minimize.

Bob Wilson