Not sure about the rolling resistance of aftermarket tires but I noticed since they are a bigger tire and they are all heavier. This would affect mileage a bit plus acceleration. Not by much obviously but I'm thinking I will stick with the stock toyo tires when I need replacements. Decent all around tire. Ride, handling, all weather. Plus light weight. Mazda skyactive cars are all about getting the weight out, getting the heat out, and Jinba Ittai. Low weight = more efficient, better handling. Low heat = higher compression and better efficiency. Jinba Ittai = Driver and car as one - responsive, tactile feel.