Block Heater Analysis

[Eli]

Last weekend, I installed the block heater in Insight #3. Installation was a breeze. Remove block drain, insert block heater, torque down, refill and bleed coolant system.

All I can say is wow. Anybody who takes frequent short trips in the Insight should look into one, IMO.

Unfortunately, the analysis reveals that it's not quite worth it for me from a pure cost standpoint. However, it could be different for you depending on how much electricity is locally for you.

It's not very cold here yet, but there's something to be said about being able to have instant heat when it does start to get cold. Seeing 65MPG+ instead of 45MPG is also worth something to me. Plus, it's better for your engine. My engine would never fully warm up during my two mile, four times a day commute. This is terrible for your oil; the fuel dilute on Insight #2 was nearly 2% due to short commutes.

Through the 5 months of winter 2010/2011, I averaged 42.6MPG due to the 2 mile commute. Electricity here is 12.7 cents per kilowatt hour.

Here's the data so far:

Block Heater Analysis Spreadsheet

I'll be updating the spreadsheet each day.

[Need4Speed]

Eli:

What brand/part number block heater did you install?

[retepsnikrep]

Nice idea more data the better. It might not be cost effective but on a cost V comfort & practicality analysis like having a heater and demister that work straight away the cost is really irrelevant within reason IMO.

[rhall]

Nice data Eli. Studies I have seen indicate that there is no gain after 2 hours and it's diminishing returns up 'till then. Still, as retepsnikrep says, the benefits are easily worth it.

[Eli]

Yeah, I'm still tweaking the amount of time that the timer is on. I need to get a digital timer as the rotary one I'm using isn't consistent in when it turns on it seems.

The block heater draws ~400 watts, so I'm at about 3 hours now. I'll keep notching the time down to see how coolant temperature behaves. Like I mentioned though it's not very cold here yet - when it starts getting down into the teens and twenties, I might have to increase the time again for it to come up to temp.

Need an engine blanket.

The great thing is that it's just much easier to get good MPG on the short commute, as you can see I'm still experimenting with it. I can utilize lean burn much more, the car goes into autostop at each of the 4-5 stops I have.. it's great. Before even if I drove very conservatively, I may have been able to raise my MPG by 4-5 points, but not the 20+ that is typical with utilizing lean burn. Warmup mode really sucks it down.

Auto stop will disappear once temps drop below the 40s.. wonder if I can "fix" that problem.

[Eli]

Spoke too soon, didn't get auto stop this morning even though temps were in the mid 40s like previous, dunno why. Affects my overall MPG quite a bit on such a short commute.

Coolant temp was still ~140 even though I notched the on-time down again, so it's likely I'm wasting quite a bit of electricity. I'm going to try for 2 hours(0.8kWh) tomorrow.

[Eli]

Originally Posted by Need4Speed

Eli:

What brand/part number block heater did you install?

It's an OEM Honda heater.

Part number: 08T44-SV4-100

[retepsnikrep]

You need to move the external temp sensor and put it somewhere warmer for a start like near the block.

[TopFuelTim]

Hi Eli,

Thank you for the heads up on the engine block heater. Just ordered mine from Majestic Honda. Dumb question. Where on the engine is the block drain located? I have not looked at the engine yet, but will be looking into doing it in a couple of weeks.

Thanks,
Tim Glover

[Need4Speed]

I think I will need to install one also. I assume like all the others I have used in the past that I just need to remove a freeze plug. What one did you put it in?