I am going to buy a full-size spare for my Forester. Tire rack recommends a 17 by 6.5 steel wheel. The book says the Forester has a 17 by 7J. Will the half inch make any difference? The 225/60 R17 tires might fit differently on the 6.5-inch wheel affecting diameter. The tire rack guy said it wouldn't matter for distances of 50 miles or less.