I was planning to switchover to GC on my next OC but some threads here have mentioned GC's high viscosity at certain temps. I thought it would be great for cold weather use given the 0W-30 rating. I'm now using M1 5W-40 in my 2005 Subaru LGT. We can experience winter temps down to around 0 degrees Farenheit here in Maryland. Any opinions would be appreciated.