I had an interesting email from a guy with a story about using 20w60 of all things in Australia's alpine region. Well he had problems at a reported ambient temperature of -2C, had to push/roll the car to the base of the mountain and let it warm up a little before he could start the car and drive off. He was under the impression that a 20w was suitable for climates down to -15C and that the oil must have been defective. It's obviously not ideal, but I would have thought there would not be a problem at -2C. Could it possibly be too much to ask of a 20w60 or was the oil indeed defective? From what he was saying the stuff was like glue at -2C from testing it in the fridge.
Now from my Toyota owners manual, -7C is the minimum suitable temperature for 20w50. He said he tried another brand and 20w50 and did not have any problems after that so that was proof the oil was defective.
Now from my Toyota owners manual, -7C is the minimum suitable temperature for 20w50. He said he tried another brand and 20w50 and did not have any problems after that so that was proof the oil was defective.