I just bought an 05HAH with 29,000 miles on it. It has been in the 60's and I'm getting 27mpg in a 60 mile work round trip. So with the change to cold weather formula's in my area, will I have drivability issues? My HAH runs really well right now (I came from a 2006 Corvette Z06, so some adjusting is taking place) without any issues. Keeping my fingers crossed.