I think it depends on how cold it gets where you live and if the car will be outside or in a garage. I lived in Mn most of my life and block heaters are very commonplace. I now live in upstate NY where it only gets into the 10-20s and I did not get it, but I can park inside. If you park outside and it is common to be below zero at night, it is not a bad idea as long as you have somewhere to plug it in.
Years ago when we had winters in Illinois, I left my Chevy inline 6 parked on a friend's driveway overnight (no block heater) on the river bluffs near Quincy. It went down to -15f, and next morning it was too stiff to turn over. I had to wait until afternoon to drive home.
I know you are supposed to plug in the heater overnight to keep the engine from freezing; if you forget, does it speed things up much if plugged in the next morning, bsox? I remember driving through small towns in the upper plains with electric outlets outside motels for the convenience of customers.
You seldom find one on a dealer's lot, but I always include one in a special order. Not very expensive, and I always think it maybe useful to me or the next guy some dark and frigid night on vacation. I always pack an extension cord (with drop light) and electric charger anyway when I'm on the road.
Yes that is pretty common place in Mn. A lot of apartment buildings do the same for people since there are not garages. I don't think you have to keep them plugged in overnight though. A couple of hours at the most usually warms up the fluids enough to start-er-up.
They used to sell dipstick engine heaters, so it can be added later if need be. The engine block heaters of days yore were put into an engine case - I believe instead of one of the expansion plugs.
Now, I believe Buick has it so that the coolant is heated up. This may be the best way to do it. My Mercedes has a coolant heater circuit that comes on when the engine is cold to warm it up. Otherwise, the diesel engine, which is much more efficient, would not heat up that well.
I once owned a V8 Grand Prix that had (2) 750 Watt Engine Block Heaters that was so effective, after being plugged in overnight, you could start up and immediately have warm air coming out of the heater and you could also drive away without warming up the Car. Back then we had Awsome Winters in North Dakota.
By all means, if you're in a cold climate, Engine Block Heaters is the only way to go, regardless of the Cost.
I wanted to add some details to this topic, in case someone does a search for engine block heaters.
I am in Colorado and ordered my Enclave with an engine block heater. When it arrived, I had to find the plug(the salesman didn't know where it was located and service was closed). It is wrapped up on the driver's side near the front of the engine compartment.
On the cord is a tag that says there is a thermostat in the cord that will not let the engine block heater come on unless it is below 0 degrees. This information was not available anywhere else that I had looked to find out about the engine block heater. I was kind of disappointed that it wouldn't come on until it got that cold. It would really be nice if you could start the car when it is 10 degrees and immediately get warm air out of the heater, but that is not the case.
I am not sure I would have ordered the heater if I had known it wouldn't even come on until it gets below 0 degrees. That's why I am adding to this topic, so others will have the information that I didn't have to make an informed decision.
I hope no one is too upset about my resurrecting an old topic to add some information to it.