Greetings All,

You've got to remember that you are heating a sealed pressurized system. Trust me you are not getting any evaporation taking place with your block heater plugged in unless it is able to overcome the pressure of the radiator cap on the reservoir. You'd definitely have a hot block on your hands when you turned the key to the start position. Would probably read the max temp on your gauge. For those thinking about leaving their Benz plugged in for days on end without driving the car, I'd recommend you put it on a timer and plug it in the night before driving it. You are just using electric that isn't necessary for the car to be ready when you are. I don't think you'd do any damage to the engine, but the bill will be more than you care for. I'd just give the three to four hour warm up on those single or low teen digit days, and leave it off the rest or the time.
Overall, I'd say that anything that will heat your block up to at least 40 Degrees C to aid in starting temps, and as a bonus you get heat to the feet quicker has got to be better for your engine. Those that don't use a block heater I would recommend they allow their engines a few minutes to at least liquify their oil before tromping on the accelerator. Just my thoughts.


Charles

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'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan