Scottoilers recommended alternative with detailed explanation in this thread..

I'm in northern VA but began using a Scottoiler in San Antonio, TX (on a Trident in 2000). Mine is an older unit that only has more/less and it is kept on the very low side. I use 90wt in the summer (generally over 70) and Scott lightweight (or a mix of 30wt & 90wt) in the winter.