I am about to convert my car over to E85 and water/methanol injection. It is a supercharged 2.0L DOHC with a 6 quart sump. Living in central KY, so the weather does get cold. For now, drive to work is about 4 miles, and the car doesn't get up to temp for long in the winter. E85 will be most likely "harder" on the oil and my driving cycle. Currently use 5w30 conventional at 3K miles (AutoRX) and not having the car long enough to extend. I am wondering if moving to Rotella T 5w40 would be better for the car, or adding a quart or two to the normal 5w30 fill.