picked up 6qts of this at walmart yesterday, figured the price was hard to beat ($11 for a 5qt. jug). Anyways, has anyone had any luck running this any longer than 5,000miles? My driving does include some severe duty driving, my girlfriend as well. I havn't decided which vehicle I'm gonna use it in next, her explorer or my jeep. Havn't heard from to many guys running it though.