I agree, narrower is better in snow. On previous car's I went from 215's down to 195's, I remember my first several FWD cars all had 155 and they were great in snow. 3rd one was a 1990 sentra at 2200 lbs never had a though of needing winter tires. Now with 195 on a 2600 car, can't imagine not having winters.
CapriRacer would state that wider gives best MPG all else equal.
Barry's Tire Tech
7%, I don't think we know his 16" tire size he might already be getting that, 7% + LLR might make a difference.