Yes, it's pretty thin stuff. I run synchromesh in my tranny and Redline 75w-90 in my rear differential. Many people run synchromesh in all parts of the country - texas, socal, florida, arizona, you name it.
fwiw I bought Redline MTL & Redline MT90 to put in my tranny, but it's just sitting there ... the synchromesh is working so well I haven't had reason to switch it out.