I just need to know if the Fram HP4 Can be used on a Merc 525 in the upside down position where as the threads are on the bottom?

With all the posts about Oil and Filters I cannot seem to find it to be sure. Doesn't it need the anti-flowback valve?

Also can the Fram be used with full synthetic Oil such as Amsoil 2000 20-50?


Thanks!!

It needs the anti drainback valve, which I believe the HP-4 does not have. As far as Amsoil, I've been using that filter with series 2000 for 5 years with no problems.

Do you know which one has the anti drainback valve. HP6?

Thanks Ray

good question, and I honestly don't know. The way their web site is worded, it makes it seem like none of the HP's have it
http://www.fram.com/products/oilFilters.php