This year it hasn't hit -40 yet, but starts at -35C. It starts happier when block heater plugged in even for 1/2 hour. I use 15w40 dino oil.

I found the best way to block the radiator is to cut a perfect radiator sized piece of cardboard and unclip the rad, tip it back, and slide the cardboard down the front of it. Then clip the rad back. Takes 2 minutes. Perfectly blocked.

I also block the oil cooler rad with a small piece of cardboard jambed up under the bumper on that side.

I also use, yes, big chunks of quilt batting / stuffing poked around the top of the engine so air does not flow over the top of the injectors, and around the fuel pump. The batting is so puffy it meets the hood liner when its closed. Engine cozy anyone? Just keep it away from the fan belt.

I read the other day, hot weather is actually harder on batteries than cold. In the summer you do the damage to the battery and in the fall / winter the cold crankcase puts a maximum demand on the battery so it is seen to fail at that point in time, but the damage was already done. Batteries work fine cold, so long as they are not frozen, then they don't work very well at all.

Below -40 all season tires take time to round out the flat spot from having parked.

At -50 hitting a pot hole with a cold tire can shatter it.

At -60 if you pee outside it freezes mid-air with a crackle and pop sound before hitting the ground.

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Cheers!
Scott McPhee

1987 300D