Yup I have been using 15W-50 for almost 2 years and have no lifter tick. Well she will tick a bit after running hard at MSR, but it stops before I am back to my parking spot. Befoer switching I tried everything with little to no results. I also use the Purelator Pure One filter for the Honda like Iain does. Not only did Mazda change the filter design and size for the Miata but so did Purelator I like the larger size of the Honda filter and it even says it has the anti-drainback valve right on the box Bottom line, is it is cheep insurance compared to ruining a good motor.