Dragon5126
New member
the 10w/30 is used in MANUAL transmissions in EXTREMELY COLD CLIMATES where regular gear lubes wouldn't work due to being to thick from the cold, Other than Alaska, I wouldn't use it in the US, since it thins out too much when heated, and gear lubes function due to extremely high viscosity which causes them to stick to the gears and transfer to each other as well as through being slung/splashed around.
