If 30 wt won't work for you because you drive in October and November, then I have troubles being that I drive 30 wt year 'round. It gets pretty chilly here in mid-winter, probably about as cold as November in the the state that looks like a kitten, er mitten.
My opinion: drive it April to November using 30 wt. When it is blustery cold, chances are you aren't driving it anyway.
Just my contribution to the 50-post thread.
Bill
