block heater questions.
 

Does block heater save any money (on gas and electricity) ? Can I use it in winter when car is turned on (block heater plugged into cars cigarette lighter) so it will warm up faster(when coming home in cold winter midnight from work). Can block heater cause to much stress on head gasket (Uneven expansion of block and head(s)). Or dipstick heater is better solution than all of the above?

A block heater is a heating element attached to the motor. I like a block heater and an oil pan heater. They are usualy 110 volt (I have used a colman stove to heat the engine of a car so that it would even start in some -50 degree weather) About 2-3 hours plugged in will get the engine warmed up quite a bit, you unplug from the outlet start the car and drive off.

The heaters are usually a prestart kind of thing as a car will typically come up to temp pretty well on it's own if you were to use 12 volt converted to 110 to run the heaters you would need quite a bit of power as they are in the 200-1000 watt range depending on how much heater you are using. If you went this route you would have to use more fuel to run the alternator much much harder to keep the battery up, much better to just have a cool engine for a little while. Can you plug in where you park your car?

A dipstick heater is kind of a temporary setup that really does not work too well (as are the magnetic type) as you only have a couple inches of oil in contact with the heater as well as a couple inches of metal where the dipstick plugs in. A block heater is a much better option.

I (and many others in northern climates) have been using block heaters for many years with out stressing any of the gaskets in the engine. The level of heat does not get the engine anywhere close to a stressful temperature as metals conduct the heat from the element very well. There are many bolts, water passages and other heat conductors from the block to the head so any significant thermal expansion differential is pretty unlikely.

I use my block heater year round up until temps hit 90°F outside.

I know that the instructions for my block heater say to NOT use while the engine is running.

Your electricity should be way cheaper than a gallon of gas so using the block heater two to three hours before you drive will save gas.

Plus, there is less wear/oil consumption to the engine.