I searched UOAs and came up empty...I am thinking about putting Amsoil Series 2000 0W30 or Series 3000 5W30 in my son's '94 Nissan Hardbody Truck. "Context": has 111,000 miles but uses no oil between changes; currently using Valvoline Maxlife which I want to get away from; he puts about 6000 miles a year on it, mostly highway but he will probably be using it to get to class (he's in college). Some of the miles are hard miles because it is his "get to skiing" truck and he occasionally has it in 4 wheel drive but mostly 2 wheel. The trip to the ski areas is a long uphill (100 miles) from Boulder CO (and he makes the trip 10-15 times per ski season). I'd like to go to Amsoil because I want to reduce the number of oil changes per year (he is not a do it yourselfer and I am not crazy about Xlube) plus his filter is a bear to get to (under the exhaust manifold and an awkward grab). Would really appreciate knowing what you think or if you have a better idea. Thanks.