I've been reading a few things here where you'll are raving about these two brands of oil for your car. In the past I have never cared what brand to use but for some reason all this talk has me wanting to get one of these and even go as far as changing the oil myself which I haven't done since the late 80's on a crappy Mercury Lynx.
Is there a difference between these? I did some research and as for Royal Purple it looks like I can score the oil but not their filter unless I want to go to PepBoys in Chicago, which I don't. I couldn't find anyone as of yet that sells AMSoil near me but I'm still looking.
Anyone had the mpg or performance improvements and longer life that these both say they give?
More importantly what are some of the drawbacks to these, not counting the price?
Take care, Gary