Effect on Hill on Cold Temp Efficiency?

[maximilian]

I've been having a conversation about maybe getting an engine heater since my area has very cold winters. Since I live on a huge hill and can coast for almost 3.4 miles with little need for power (my last car didn't need any once I was out of the driveway) and the engine is warm enough to provide heat by then (I have no temp gauge), how bad do you think it realistically is? I don't drive much and will relocate soonish to a less frigid area, but the question seems interesting. Oh yeah, I keep the car in a garage and I turn to go downhill for almost all of my trips (greater than 95% easily). I don't turn the engine off (not quite comfortable with that yet) and it's a manual so I coast in neutral. So it is doing some cold running, just at very low levels

[Jay2TheRescue]

A block heater could help you with that...

-Jay

[maximilian]

But would it save more than the cost & effort to put it in?

[theholycow]

In previous threads, it was determined that they're cheap and easy to put in.

[Jay2TheRescue]

Yes, I've even seen block heaters that replace the dipstick. Its installed in seconds. Very easy.

[maximilian]

Originally Posted by theholycow

In previous threads, it was determined that they're cheap and easy to put in.

Yes, I saw those, but my special starting consideration changes things. A small amount of power put out during the cold part of running should be less wasteful than a large amount, I'd think, but my intuition isn't developed enough for this question to come to a final conclusion.

[R.I.D.E.]

In your situation I would use a block heater. You're already parking in your garage, so you probably have a convenient electrical outlet.

The downhill run gives you the chance for great mileage, but the cold engine running and warming up at idle uses much more fuel that it would idling when it was already warm.

I never let my engine warm up without using the fuel for moving the vehicle.
On a cold start you have oil pressure by the time the engine has run 1 second, as long as your oil filter has a check valve, which all of them should have by now.

It may be a tossup between cutting the engine off on your 3.4 mile downhill glide. It would just allow the engine to cool off again.

regards
gary

[maximilian]

I was thinking that pumping would heat things up, but I am in neutral! Of course! (hits head with hand) I might as well be sitting still, idling to warm it up; I just happen to be coasting instead. Well, now I can peruse the existing threads to see which type is best. Even if I'm moving somewhere warmer, if they're cheap enough and don't mess with my warranty I'll go for it. Thanks all.

[s1120]

How warm is the garage?? If the garage is a lot warmer then outside, I would think you would be splitting hairs using a block heater. Ya, it will help, but how much?? Think you would be good off with some kinda grill block to reduce the heat loss through the rad during your warm up coast.

Frankly I think you would be better off heating the tranny in some way. Warmer trans fluid will allow it to spin with less resistence. Maybe set up one of those halagen work lites under the car to heat it up??? they put out GREAT heat [I use them for my tractors in the winter] and you can set them on a timer to come on a hour or two before you leave.

Just something to think about...

[maximilian]

I'm getting a car computer soon, so I'll have it for next winter. It shows cooling water temp, so I can track things. Since I drive such a consistent route and I keep a gaslog, I also have very good records of the winter miles I drive, so I can work out a good estimate of the number of trips. Then it's just a little math to see what I might save.

[theholycow]

Those lights definitely put out lots of heat. I'm always deathly afraid of starting a fire when I use them.

http://www.harborfreight.com/cpi/cta...emnumber=66433


A flat adhesive-backed fish tank heater might do the job if it stays stuck. Thinking along those lines, I figured there must be stronger heaters of the same design for RV waste tanks, and sure enough there are:
http://www.ultraheat.com/shop/Tank_H...nk_Heater.html


Unfortunately, they're $100 which puts them far, far out of "pays for itself" range. It might make more sense to retrofit a block heater into the transmission.

I'm not sure I agree that it makes sense to heat the gear oil in a manual transmission, though. I don't think it takes long to get to operating temperature. It's unaffected by whether the engine is on or off. If you really wanted to deal with it as a problem, you could use a premium synthetic multi-weight gear oil.
http://www.redlineoil.com/products_g...5&categoryID=6
Again, it won't pay for itself...

[maximilian]

I already have a couple halogen lights lying around. My ex got a wicked burn off one once. Oh yeah, forgot. The garage isn't heated but it is integral to my house and has 14" thick insulated walls, although garage doors are like R-10 or something and they don't seal anywhere near as well as a normal door. The walls it shares with the house are 2x4 insulated and the ceiling has 2x6 insulation in it (above is a heated space). Never measured the temps in there before, however. The last few years have been quite warm. A while ago I got satellite TV installed one day it was -30F. I offered to let the installation guys come back another day, but they wanted to get it over with. More dedicated than I am, that's for sure.

I also need to consider the hassle of plugging and unplugging the heater. Not a huge deal if the savings were large, but convenience is worth something.