I still like Amsoil. I use it for most fluids on my 4Runner. Be aware that you can't realistically use the oil past something like 7500 miles unless you also get a dual remote bypass oil filter that filters it really well. One of those 2 large filters has a much finer filter media. Only in that situation can you use the oil for a really long time (like the claimed 25,000 miles) and THEN it still has a chance to look like new after all those miles, and you can do the oil tests to see how long you should use the oil. Without that additional ultra-filtration system, it still gets dirty and looks bad like any synthetic oil after several thousand miles. So there's no need to do the oil tests to see how long you can push it since the oil is obviously dirty and black by that time.

It's nice that the preferred customer thing can be purchased for only 6 months at a time now rather than per year. Then you can stock up on all filters and fluids for quite a while so the membership is a very minor expense.