What I have read, biggest impact to range comes when you go from 20 to 21, not so much when going from 19 to 20. 21 seem to impact range the most radically. Maybe not everyone feels that way. Good point about the nf0, maybe someone just have to try and see what happens :)
Was thinking that the biggest hit to effiency comes from tire widith when you go from 20 to 21 inch. Has anybody put 245/40 and 285/35 vs the standart 265/35 305/30. I would think grip is not an issue with narrower tires and efficiency would be better. Me and the wife are getting a 4s soon and...