I went -1 on the front to a 15 tooth, loving it, not a great difference in highway rpm, acceleration and low, mid power alot better, and i don`t really care about mpg, for the same reason i drive gas guzling v8`s. way i thought about it wa,. i start with the front sprocket, see how it goes and suits my personal need`s also due to it being the cheaper of the two and if i still wasn`t impressed change the back out to -2