[RedDevil]

Tire width does not help with rolling resistance imho. It may seem like so if you run the narrow and wide tires on the same pressure (especially when that's quite low) because the narrower tire would have to flex deeper.
To compensate for the narrower thread you have to increase the pressure to the same ratio to get a fair comparison. Then you'll see the narrower tire win hands down.
Narrower tires are less prone to aquaplaning too; as the risk of aquaplaning rises with higher pressure it is tricky to raise the pressure on tires that wide.
Narrower tires will allow for far higher pressure before losing traction.
As increasing tire pressure is the one mod that effects FE most, go as narrow and up the pressure as high as you dare.

My Insight is sensitive to side wind, but that effect has almost gone away since I raised the pressure from below OEM to way above.
My Insight is at 175 width winter tires now. The Accord would need to weigh over 2 tons to get the same thread pressure as mine if you go for 245 mils. I'd rather go for 205's... but I'm not you.