Switched to my winter set-up about 4 weeks ago, 17 inch square vs 18 inch staggered summers. I've got about 800 miles on them now and have noticed that my gas mileage has improved by approx 1.7 mpg! I'm loving it but wondering why. Driving me crazy trying to figure out if it's due to the narrower width, lighter wheels, softer compound, non-RFTs, different gas etc etc. This morning on my way to work, I'm cruising up the highway when it dawns on me, there's no technical reson why my mpg is higher, I'm DRIVING SLOWER WITH THE WINTER SET-UP! Keeping my speed at 60-65 mph vs 80 = 1.7 MPG. Took me a month to figure it out.