Engine block heater in fall, spring & Summer - Fuel Economy, Hypermiling, EcoModding News and Forum

TXwaterdog · 10-10-2011, 05:34 PM

*sorry about posting in the wrong place! My bad- 2nd post

First off, Thanks for all the info. I've been lurking for about a week reading posts and learning ways to increase my fuel mpg. So far I've gone from around 32-35mpg up to 37-39mpg just by using some simple things I've read here. (44psi fronts, removed spare tire, took airbox cover off to suck in warm air). I'm learning how to drive my car to consume less gas and winter's coming up. I've seen many people posting great results with using engine block heaters and the like.

So, here's my question: Have you guys who utilize heaters seen any benefit to always prewarming the car? I'm in Austin Texas and it doesn't really get lower than 40 degrees very often. Our winters linger around the 50-60 range. It's not exactly freezing out there but I'm wanting to increase my mpg and engine life. Do you think preheating even in 90 degree weather is beneficial?

*on another note, has anyone used a 12volt ceramic heater to warm up the interior? I was thinking of moding one to flow through the AC vents via a switch.

99LeCouch · 10-10-2011, 09:20 PM

Around 40-45*F you'll see benefits. Otherwise I haven't noticed one from the oil pan heater on my Cruze. I still plug it in just to see if it does work.

brucepick · 10-10-2011, 09:25 PM

My view is, since the heat you get from electricity costs less than the heat you get from gasoline, any preheating of the engine should give you benefit. Unless of course the engine never gets a chance to cool down from operating temp.

Remember, when the car needs to heat up the block, it will run rich because that's how the computer is programmed. Much of your warmup fuel will be burning in the exhaust system where it doesn't heat up anything you really care about, never mind giving you efficient motive power.

TXwaterdog · 10-10-2011, 10:36 PM

I havent seen anyone using a heater on the gas tank... Do you think warming the gas in addition to the block has any merit?

slowmover · 10-11-2011, 09:12 PM

If the daily drive is under 30-miles (22 miles at 50 mph according to EPA( then pre-heating engine oil, coolant, trans and axle fluid would eventually (long term) show an increase.

This topic comes up on diesel pickup boards as diesels are cold-blooded beasts. One correspondent noted that 90% of the heating benefit could be seen in 90-minutes or less for most situations.

In other words, one might look to see what op temp is for those fluids; what combination of KAT or other pad heaters plus an installed electrical harness to run them would cost after DIY installation; plus the kwH cost on an annual basis to see if the fuel burn reduction worked out.

I tend to think it would, if not for any other reason than component longevity where the owner is scrupulous about fluid working life. But one must first look to see if the vehicle is ideal for use the next 10-15 years over a projected miles limit.

FE is only a sub-set of Economy. The other factors must weigh as heavily to go this direction.

Nevyn · 10-12-2011, 10:25 AM

If I'm cold, I drive worse. I like my 400W block heater.

That said, my commute is long enough that it doesn't really make a difference overall - but it does save time in that I have defrost WAY faster, as well as some warmth for my toes. If I'm warm, I drive much more 'zenly' than if I'm cold.

Diesel_Dave · 10-12-2011, 11:33 AM

I've been plugging in the block heater on my diesel regardless of the weather. Now that's it's getting cold I can tell more of a difference on startups. I've got oil pan heaters ready, but need to get a little bit of time to slap them on.

Obviously there's more benefit when the weather is cold, but I can't really think of any significant reason why pre-heating would ever hurt your FE. IMO, one of the biggest benefits to pre-heating is related to the oil, because of 2 things. First, when the oil is cold your oil pump does a whole lot more work to push the oil through the oil filter (because it's thicker). Secondly, when you start up, your oil needs to find it's way through all the different passages and into all the bearings, etc. Until the warm oil gets there, your friction is going to be much higher. That also decreases your engine life as well.

Remember too, that operating temps for coolant is ~200 deg F and oil temps are up in that range or higher so even 90 deg F is "cold".

TXwaterdog · 10-12-2011, 01:25 PM

Has anyone used a solar panel to power the heatplug during the day while it's parked at work or the mall? If so, What has your experience been with using it?

meelis11 · 10-13-2011, 08:04 AM

Probably solar panel cannot make enough power to warm that heat plug. I think electric heating is probably worst use for solar power (photovoltaic cells)

Diesel_Dave · 10-13-2011, 09:59 AM

Quote:

Originally Posted by SimonSellsAustin

Has anyone used a solar panel to power the heatplug during the day while it's parked at work or the mall? If so, What has your experience been with using it?

My heater is 750 Watts. You better find a mighty big solar panel to power that! That being said, I have thought that you could take a spare car battery and a inverter to accomplish the same purpose. You could charge the battery at home at night, then use the car battery to pre-heat during the day, without the risk of draining down your main battery.