I hope the experts on this board can tell me wether the daily use of a block heater will affect the life of the oil used in my vehicle ('98 Chev K1500, 4.3 l V6). I'm sure that many of you will say that in my moderate climate (Vancouver, BC) the use of a block heater is not necessary. I agree but I believe that it is easier for the engine to start if the oil has been heated for a couple of hours. What I also like is that I can immediately defog my windows (no AC) and that the cabin is warm within a minute or so of driving. My truck uses a dual filter (bypass) system and all fluids are synthetic. Oil (presently Amsoil 5W-30, previously Mobil 1 5W30), 10-12 K oil change intervals. I'd appreciate any comments.