So much i've tempted todo something similar for my car - as winter driving hampers fuel usage badly.... tempted to see if preheaters are worth it or not
You could be onto something there but the preheater on my car is not going to get the engine anywhere near working temperature. It just enables the engine to avoid wear while being started when extremely cold and enables the oil to be less thick. I will turn the heater on now for a few hours while the car is in the garage and let you know what difference it makes to the engine temperature. I am supposing the engine is not going to be very noticeably warmed even while garaged unless I measure it with a thermometer.
While the car was in the garage at 8C I put my preheater on for almost 3 hours and found the preheater was boiling the coolant and the parts of the engine i could measure easily were almost 50C. The engine temperature gauge was on the first line up from bottom ie it was about 1/8 of an inch from zero. The garage temperature had risen to 11C.
While the car was in the garage at 8C I put my preheater on for almost 3 hours and found the preheater was boiling the coolant and the parts of the engine i could measure easily were almost 50C. The engine temperature gauge was on the first line up from bottom ie it was about 1/8 of an inch from zero. The garage temperature had risen to 11C.