Not going to state an opinion one way or the other on this, but after decades of religiously changing oil on a 12 month basis, even with 1K -3K mileage, over the past few years I've occasionally gone a couple of years with cars that I'm driving less than 1.5K per year, have top grade pure synthetic oil installed, and are always garaged..
Anyway, I did find the testing and the results interesting.
Gary
Anyway, I did find the testing and the results interesting.
Gary