Best 2nd Gen Prius winter tires?

[mpg_numbers_guy]

Parents are looking for winter tires for my mom's "new" 2008 Prius. The Continental 185/65R15s on there will likely need to be replaced next summer and based on Prius summer tire research on here will probably be going with the Bridgestone Ecopia LRR 185/65R15s, but she needs winter tires for the Prius. Which winter tires offer the best traction for the lowest MPG loss for the 2nd gen Prius?

[airbiteses]

Nokian tires are almost the lightest and least burning and then Continetal tires.

[mpg_numbers_guy]

Update in case anyone comes across this thread. While we would've preferred Nokians, we got an excellent deal on Michelin X-Ice tires.

She averaged mid 40s MPG in the depths of winter on the tires, and now with things clearing up she's getting high 40s to mid 50s.

Tires are at sidewall max of 50 PSI. Traction has been excellent, although at higher winds the vehicle does seem slightly unstable due to tire pressure.