When I was living up in Butte, MT. It got super cold, days on end without breaking 0 without factoring in the wind chill. Tried 5-30w and a new temp sensor, but after collecting quite the collection of fried starters went to multiple block heaters. Got a magnetic one for the oil pan and a inline heater for the lower radiator hose, made a world of difference. Napa sells both and they're about $30 each. To me it was the cheapest fix for a seasonal issue.

98' BBJ Grand Laredo 5.2 locked and loaded,.01' Gen III XLS. Frankenmonty lives on in another.