I sent a very detailed email to Amsoil comparing their website specs to that of Ford's as it relates to Mercon V and Mercon SP ATF fluid. I also sent links to the industry reports regarding how Mercon V and Dexron are different as well and should not be combined or rated for dual use.

Instead of a reply email they called me back here at home (probably to see who I am and what I do and why I am asking such a technical question)???

For one, I was impressed that they called. The gentleman's name was Kevin (not sure of actual department but he spoke like an engineer and not just a C/S guy). He stated that Ford has published the specs, but has not licensed the use of the Mercon SP trade name for use on bottles... but they can still claim compliance, but not use the trade mark name (whatever that means)?

He claims that the specs are very similar and that at different temps they can meet the specs and meet performance specs due to the PAO synthetic components of their oil.

Much of what he told me went over my head... but they did sound confident that their ATF fluid is that good.

Bottom line and my conclusions:

1) I am sure it is a good fluid - Amsoil.

2) I will continue to use Mercon SP from Ford (warrenty concerns).

3) Motorcraft Mercon SP is synthetic and costs less!!

4) Amsoil may be a good lfuid but is not Mercon SP licenced and therefore not recognized by Ford... and who knows, may not be what my tranny needs?

5) Bottom line... use what you want, but do you want to take Amsoil's word that their oil or ATF fluid meets specs, or use one that does meet specs and/or is API registered or is Ford "approved"?

6) I vote for spend less and get more - Motorcraft Mercon SP!!!!