Cadillac has used them for several years. They started at around 4000 miles max, then went to 7500 max, and then 10000, and as of 2000 or so are now at a max of 12,500 miles for conventional oil. They swear by them and strictly state to follow the oil life indicator. I, however, have not followed it. In the cold winter, it only went to about 1400 miles before wanting an oil change. I guess idling, short trips and the shear cold temps. In that case, it was great, but the 12500 miles for conventional oil...not me!
