Right now, I use whatever I have stashed, since it's free. However, if I was buying at retail prices, I'd use Valvoline Maxlife Conventional or Maxlife Nextgen 5W20 in my Ford vehicles and 5W30 in those that call for it. At our local Walmart, both are sold for about $17-18 in pretty much all possible grades, which is not bad at all. There have been a few good Maxlife UOA reports already, and I like the fact that Maxlife version has a bit higher TBN than the normal oil according to Valvoline's product sheets. However, besides that, does anyone know what else differentiates the Maxlife oils from the regular ones?