Rich I did not really have the problems with Amsoil it just a pain in the ass to get You just can not run down to pep boys or the zone and pick up a quirt
moble one when they changed it I had a slugging problem and every morning on cold start had a lifted hag up
when I went with royal purple the lifter problem went away
IY was when I changed my oil in my rears witch had 75x140
and switch it out with 75x90 royal purple max gear that I saw a major deference
this past summer when gas was haging on to 4.00 bucks I could go ON I 95 and set the cruse control to 54 mph and was getting about 19 mpg when I changed out every thing with royal purple changed the plugs with NGK V tec and did the same test and she hit 28 mpg I could not belive this so my wife also has the same year jeep with the same in line six and I did the royal purple thing on hers and ended up with the same results I could not believe it and have tested this time and time again and it still doing fine
so to say I had good luck with royal purple amsoil seamed ok but I hate the way they marketed it like a mlm I like to go and buy it when I need it and not go though hoops
also there is a will good report for Dr Hass on oil thickness
a little long but good infor This is why I am running 5x 20 instead of 10x30
here is the site
http://ferrarichat.com/forum/faq.php?s=2...otor_oil_basics
Also In the city we were getting 10 mpg on a in line six now we are getting 14/ 15 city driving I never belived that oil could make a deference but hey it doing it