Originally Posted By: Tim H.
I haven't seen a definitive answer on either side..
Tim - Amsoil (in the past) called out (for example) a list of best fit oils, such as 0W-20 and 5W-20 and 0w30 when the manufacturer only called out 5W-20. The problem with this, it caused much confusion with the consumer. He didn't know which to use. So at first Amsoil only did a Best-Better-Good type of approach, ie saying (for example) 0w30 will be best (and of course most expensive). The customer would look at the manual and comment that 0w30 wasn't listed. So another round of Q and A would ensue. Since Amsoil has completely changed their line-up to have SS series with more than just the 0W-30, they can now recommend the best product in the line up and still have the viscosity match the requirement. Which is easiest to do just by simply parroting the All Data information.