I doubt it would fit the 4.2. But, since you have them already, just do a test fit.

BTW - narrower tires are better for winter anyway, they can cut through the snow better vs. a wider tread that might just float over the snow. However, you 225/45/16 are too small overall diameter compared to the 255/40/17.

Yes, the Phatnoise is plug-n-play.