[MetroMPG]

popimp - where do you live, and how long is a typical trip in the car?

If the answers are "somewhere cold" and "short", then a block heater would be worthwhile. You'll need something that packs a punch though - no wimpy 300w units.

I've installed a few and they vary from intermediate to difficult, depending on the type you get. (The best ones warm the coolant directly - vs. bolt-on or magnetic radiant heaters.)